Evidence Update–Is Surgery Really Necessary for Dogs with Cruciate Ligament Ruptures?

A couple of years ago, I wrote about the question of whether or not surgery was better than medical management for dogs with cranial cruciate ligament (CCL) disease. Here was my conclusion at that time:

As is almost always the case, the evidence is not of the highest possible quality or unequivocal, but this does not exempt us from having to draw conclusions and make recommendations to our clients. My interpretation of the available evidence is that overall, cruciate ligament disease causes significant arthritis and loss of function when untreated. For most dogs under 15kg, conservative management (primarily restricted activity for 3-6 weeks, achieving and maintaining and appropriate body weight, and possibly physical therapy and pain medication) can achieve acceptable comfort and function. In larger dogs, significant arthritis is inevitable and dysfunction is extremely likely without surgical treatment. No single surgical technique is clearly superior, so the choice of specific surgery should be determined by the judgment of the individual surgeon and the needs of the owner.

A recent research article has added an important piece of evidence concerning this subject, and while supporting the value of surgery it does weaken somewhat the case against medical treatment for large dogs.

Wucherer, KL. Conzemius, MG. Evans, R. Wilke, VL. Short-term and long-term outcomes for overweight dogs with cranial cruciate ligament rupture treated surgically or nonsurgically. Journal of the American Veterinary Medical Association 2013;242(10):1364-72.

The authors interpretation of the results supports the argument that both surgical and nonsurgical treatment can be successful, even in overweight large-breed or giant-breed dogs, but that surgery appears to provide a better outcome.

Overweight dogs with CCLR treated via surgical and nonsurgical methods had better outcomes than dogs treated via nonsurgical methods alone. However, almost two-thirds of the dogs in the nonsurgical treatment group had a successful outcome…

Overall, I agree with their conclusion, though I would probably place less confidence in it than the authors do.

The Study
Forty overweight large-breed or giant-breed dogs with unilateral rupture of a CCL were recruited and randomized to either medical therapy alone (a weight loss program, individualized physical therapy, and daily use of a nonsteroidal anti-inflammatory medication) or medical therapy plus surgical therapy (TPLO). Outcomes were assessed at 6 weeks, 12 weeks, 24 weeks, and 52 weeks after the beginning of the study.

There was a high rate of drop out (5 digs by 6 weeks, 11 dogs by 24 weeks, and 17 dogs by 52 weeks). The majority of these dogs (11/17) dropped out due to CCL rupture in the opposite leg, and there was no overall difference in dropouts between the two groups (9 in surgical group and 8 in non-surgical group).

Both subjective outcome measures (surveys of owner perception of their dogs’ pain and lameness and pain scores generated by the investigators) and objective outcome measures (body weight, body fat, body condition scores, and several measures generated by force-plate analysis) were evaluated at the beginning of the study and in the dogs still participating at each follow-up point.

The Results
No adverse effects were reported for the weight loss diet, the NSAID therapy, or the physical therapy. A few minor complications associated with TPLO surgery were reported at rates consistent with those reported in other studies.

The weight loss program did result in decreases in body condition score and percent body fat for both groups, and there were no significant differences between the two groups. Interestingly, while total body weight did decline slightly for both groups, the decrease was not statistically significant for either, and there was no difference between the groups.

Subjective measures, both owner and investigator assessed, improved significantly for both groups. There were no differences between the groups in the subjective outcomes assessed by the investigators. The surgery group had significantly lower scores for pain severity and interference than the non-surgical group only at the 52-week evaluation. Some differences between the groups in visual analog pain scale assessment by owners were reported, but how many measures were assessed and which ones differed were not reported, and no statistical analysis of these differences was reported, so it is difficult to assess this outcome measure.

Of the several force-plate measures assessed (5 or 6 measures; it isn’t clear from the paper), only one differed between the groups, and this difference was significant only at two of the four assessment points (24 weeks and 52 weeks).

The investigators also created a composite measure of “successful outcome,” defined as achieving both a specific force-plate measure that was >85% that of a normal dog and a subjective, owner-assessed improvement in lameness and quality of life >/= 10%. The dogs in the surgical group had higher “successful outcome” scores at all assessment points, but this only reached statistical significance at 24-week evaluation.

Strengths of the Study
Overall, this was a well-designed study. The use of both subjective and objective outcome measures, random assignment of treatment, an aggressive and consistent medical therapy program, and partial standardization of surgical treatment all reduce the risk of bias, confounding, and other error in the study. The consistency of several reported variables (such as surgical complication rate) with those reported in other studies increases the confidence one can have in the results. And the attempt to verify compliance with the weight loss aspect of medical therapy is an important part of any study employing this therapeutic approach.

Limitations and Caveats
A significant limitation is the lack of blinding of owners or investigators to treatment group. While blinding would be difficult, and possibly unethical due to the need for a sham surgery component, the lack of blinding introduces significant risk of information bias, particularly in the subjective outcome measures.

There was some individualization of surgical procedure and physical therapy treatments employed, which means not all subjects had the same treatment. If some techniques used work better than others, or if the selection of technique to be used is associated with the likelihood of a good or bad outcome, this could generate an erroneous impression of the differences between the surgical and non-surgical treatment groups.

The biggest limitation of the study was probably the high dropout rate. In general, dropout rates greater than about 20% are considered to severely compromise the data, and the overall dropout rate was 42.5% in this study. Though the number of dropouts were evenly distributed between the two groups, this does not mean the dropouts did not introduce bias into the results. If those patients who dropped out, most because they developed a second CCL rupture in their other leg, differed in terms of their underlying disease or response to treatment from the subjects who stayed in the study, this could have significantly altered the findings.

Also, as the authors themselves point out, the dropouts caused a significant loss of power in the study (though no power analysis is presented in the report), and this could lead to a failure to detect a difference between the groups. Overall, the dropouts significantly weaken the confidence we can place in these results.

Bottom Line
This study does provide some support for the contention that overweight, large-breed or giant-breed dogs have better long-term outcomes when treated with both surgery and non-surgical therapy rather than with non-surgical therapy alone. However, the limitations in these data are great enough that the case for preferring surgical intervention is not strong. The non-surgically treated patients had overall very good outcomes that, at most time points and by most measures, did not differ significantly from the patients who received surgical treatment. Additional evidence would be required to make a strong statement that overall surgery is superior to aggressive medical therapy.

While it is reasonable to tell dog owners that there is some evidence their pets will benefit more from having surgery than not having it, we must also inform them that most dogs will have a good long-term outcome even without surgery. And it is important to emphasize that even with surgery, aggressive management of weight and physical therapy are important elements of  comprehensive and successful treatment. For those owners who cannot afford surgery, or those patients who are not good candidates, there are still effective therapies that can be offered.

Posted in Science-Based Veterinary Medicine | 103 Comments

Plechner Syndrome and the Art of Making Stuff Up

Most proponents of so-called complementary and alternative medicine (CAM) are ordinary, reasonable people, even when promoting beliefs that may be dubious or even thoroughly incredible. However, occasionally I run across one of those individuals with not only a bizarre understanding of health and disease but a bizarre sense of their own relationship with veterinary medicine. Individuals like Dr. Gloria Dodd and Eric Weisman (1,2,3) appear to see themselves as misunderstood geniuses, martyrs whose insights and efforts to improve the world are resented by the less enlightened and attacked by nebulous conspiracies dedicated to preserving their power and income by suppressing simple, cheap cures for disease.

Many of the warning signs of quackery are related to these narcissistic and self-serving narratives (including the Galileo Complex, the David and Goliath Myth, and the Dan Brown Gambit). While an exaggerated sense of self-importance and a persecution complex are not guarantees that the ideas a person is promoting are nonsense, they certainly should raise a red flag and lead one to pay even closer attention to the amount and quality of evidence behind these ideas. All too often, it appears that ego alone is all the evidence these folks need.

That seems to be the case for Dr. Al Plechner. Dr. Plechner is a California veterinarian who appears to have discovered the cause and the cure for most serious medical conditions not already curable by scientific medicine. He calls his one true cause of disease Atypical Cortisol Imbalance (ACIS), though he usually refers to it as Plechner Syndrome.

What’s The Problem?

Dr. Plechner begins his somewhat vague argument by referring to the “Medical Ice Age.”

The MEDICAL ICE AGE relates to the gradual breakdown of ourselves, our animals, and our earth. As this gradual breakdown is occurring, a concentration of predisposing factors of poor health are being created. Not only are we seeing entire families of people developing allergies, auto-immunity, and cancer, but we are also seeing even a faster progression of diseases in our animals due to indiscriminant breeding, and breeding without function. The lack of concern for our earth has further allowed for environmental breakdown, contamination of our soils and waters, and the development of an unstable atmosphere…

With this present day destruction, a potentially dangerous cortisol deficiency is being created in our bodies which allows the immune system not to protect people and animals, but instead allows the loss of recognition of the body’s own tissue by these cells, resulting in allergies, auto-immunity, and cancer. This is called, PLECHNER’S SYNDROME. The identification and control of this syndrome may slow down the MEDICAL ICE AGE which threatens our existence.

He goes on to describe ACIS or “Plechner’s Syndrome” and how he believes it is related to disease:

ATYPICAL CORTISOL IMBALANCE SYNDROME (ACIS) (PLECHNER’S SYNDROME) DESCRIBES A DEFICIENCY IN THE PRODUCTION OF CORTISOL FROM THE MIDDLE LAYER ADRENAL CORTEX AND ITS INABILITY TO PROVIDE ACTIVE (WORKING) CORTISOL WHICH IS THE UNDERLYING CAUSE OFATYPICAL CORTISOL IMBALANCE SYNDROME (ACIS) (PLECHNER’S SYNDROME) AND THE MEDICAL ICE AGE. This shortage of active (working) cortisol leads to a domino effect through the deregulation of thyroid hormones leading to the production of excess ESTROGEN and the deregulation of the immune system and all of the diseases and maladies this resulting faulty immune system creates.

…The fact that these hormones (ALDOSTERONE and ADRENAL ESTROGEN) are present relates to whether the CORTISOL and THYROID HORMONES are working, and not the ESTROGEN and ALDOSTERONE, otherwise the electrolytes and the antibodies would not be working. The comparative levels refer to the CORTISOL and IMMUNOGLUBULINS and this is why it is so important to do comparative levels, including those secretions which are regulated by active (working) hormone.

This supposed endocrine disorder is identified as the underlying cause for many seemingly unrelated diseases, including:

Food Allergies: “You must realize that food sensitivities may only occur secondarily to Plechner’s Syndrome, which is a hormonal antibody defect. If this syndrome is damaged and uncontrolled, eventually the patient will develop food sensitivities to all food.”

Skin Allergies and Infections: “Most dog skin problems seem to come from a hormone antibody imbalance referred to as Plechner’s Syndrome.”

Vomiting in Cats: Of course, food allergies can cause vomiting, and this has already been attributed to Plechner Syndrome. But apart from this problem, “The 2nd most common reason why cats vomit is due to a hormonal antibody imbalance.”

Cancer: “What then is the cause of this uncontrolled tissue growth called cancer? It occurs because of a endocrine-immune imbalance that leads to a deregulated immune system. This endocrine-immune imbalance begins with a defective or deficient cortisol which is produced in the middle layer adrenal cortex.”

Feline Viral Leukemia: “…feline-leukemia victims usually suffer from a hormone imbalance. In treating more than 2,000 cases, Plechner has discovered that with an individualized hormone-replacement plan, dietary changes and regulation, the virus can be controlled, if detected early enough. There are cases in which leukemia-positive cats have become negative after several weeks of treatment, although veterinary textbooks say this is impossible.”

Other Retroviral Infections: “The cats and humans that suffer from these viruses [retroviruses], like HIV, FIV, FIP and FELV, all have a hormonal-antibody deficiency caused by the Plechner Syndrome.”

Bladder Infections:  “Chronic bladder infections in cats are caused by a hormonal antibody imbalance which as yet has not been realized.”

Dental Disease: “The plaque, on the actual tooth may not be causing a problem unless the plaque is great enough to cause the gum associated with that tooth, to cause a gingival recession leading, to an exposed tooth root problem, causing the problem, but rather a hormonal antibody imbalance that is leading to a deficiency of the protective antibody for the gums?”

Inflammatory Bowel Disease: “The cause of the IgA imbalance, IBD and other associated diseases, come from a middle layer imbalance in natural cortisol, produced by the middle layer, adrenal cortex.”

High Cholesterol: “I have found in people and animals, that when there is a cortisone imbalance, the pituitary stimulation causes an increase of total estrogen in male and female patients from the inner layer of the adrenal cortex. This in turn binds the use of thyroid hormone, and reduces the metabolism of the liver where cholesterol utilization and breakdown occurs. Automatically you can see why cholesterol levels may remain high, even after you have done everything that had been recommended.”

Epilepsy: “However, my research studies have allowed me to discover a syndrome involving elevated adrenal estrogen, causing an inflammation of all the endothelial cells that line the arteries of the body. When this elevated level of adrenal estrogen, including ovarian estrogen, causes inflammation of the cerebral arteries, a migraine headache or epileptic seizure can occur…In animals that have had their ovaries removed and in males with no ovaries, this same elevated adrenal estrogen can occur, causing the majority of epileptic seizures in animals and other catastrophic diseases.”

Cherry Eye: “What is cherry eye? This is a condition seen in dogs that relates to the tissue near the inner area of the eye. At the inner portion of the white of the eye, is a membrane that is a remnant of amphibians. In amphibians, this is a membrane that covers the actual eye, and allows the amphibians to see under water. In dogs, there is only a small remnant. But in this remnant, there is a small lymph node, often referred to as the Hardarian gland. When Plechner’s Syndrome is present, it creates an antibody deficiency. When this occurs this small gland increases in size to make up for the antibody imbalance and can reach a size when it can actually abrade the cornea and definitely needs to be removed. At this time, you should insist that your healthcare specialist, remove the other lymph node even if it not enlarged. It will enlarge later and have to be removed, unless you correct Plechner’s Syndrome.”

Plechner Syndrome is also credited with a causal role in female infertility and poor breeding performance, Sudden Acquire Retinal Degeneration Syndrome (SARDS), “Rage Syndrome,” and infestations with fleas and ear mites.

And how is this syndrome detected when it can cause so many seemingly unrelated disorders? Why a simple blood test, of course. It has to be sent to the one lab he trusts, one which will measure the particular kinds of hormone levels he believes are important (which most labs don’t measure since most endocrinologists don’t agree with his assessment), but otherwise it is easy to identify this one underlying cause of many, if not all, diseases.

While Dr. Plechner identifies his eponymous syndrome as the root of most disease, he only speculates about what causes the syndrome itself: “It may be caused by genetics, exposure to toxins, stress, aging, lack of sleep, or in combinations thereof.”

And he does identify a few other causes of ill health, though most he mentions do ultimately cause disease by generating Plechner Syndrome. He feels there are “toxins” in the environment and in pet foods, though he only identifies a few specific substances (plastics, parabens, fluoride, and of course genetically modified food crops). He also considers inbreeding to be one possible cause of Plechner Syndrome, and he has a lot of concerns about radiation. And he recommends dosing the amount of vaccine given by size, in a purely subjective way despite the complete irrationality of this approach, presumably because “too much” vaccine would be harmful.

What’s The Solution?

What does Dr. Plechner recommend as treatment for Plechner Syndrome? The mainstay of his treatment is a lifelong supplementation of cortisol and thyroid hormone for any species, both as a treatment and a preventative measure. He may use the laboratory tests he recommends to guide the specific dosing he uses, but it seems clear that he isn’t really diagnosing Plechner Syndrome since he already knows it is always present; “Every patient I have been involved with, whether dogs, cats, horses or people, all have an identifiable, hormonal antibody imbalance.”

He also recommends calcium Montmorillonite clay as a panacea for numerous conditions, including: kidney disease, nutritional disorders, “detoxification” and chelation of supposed toxins, osteoporosis, urinary tract infections, radiation poisoning, skin disease, burns and wounds, gastrointestinal upset, and more.

And finally, he tosses in a hodgepodge of other alternative therapies, including homeopathy, another “magic water” called Kangen Water, and digestive enzymes.

So Why Isn’t Everybody On Board?

The first question one should always ask about any hypothesis or new approach to health and diseases is “What’s the evidence for this?” Here’s what Dr. Plechner says:

1. I have created a successful treatment program that has helped approximately 150,000 dogs, cats, horses and people. These were patients, not only at my hospital, but in healthcare facilities throughout the world.

2. My clinical studies also show that there are high levels of total estrogen in all female dogs that are diagnosed with cancer… although these dogs no longer have their ovaries.

3. Every cancer patient I have ever been involved with, whether it be animal or human, has an elevated level of total estrogen that is not indicated with standard estrogen testing.

4. Through my clinical studies over the past 50 years, I have been able to identify a genetic and acquired endocrine immune imbalance, which can be easily corrected so that the retrovirus will not end the life of a patient.

5. With my clinical studies I have found that 80 % of the causal control will not need antiepileptic drugs to control their seizures however 20 % even on hormone regulation of the seizures may need to stay on antiepileptic drugs.

Wow, these are pretty impressive research results! Let me just have a look at the published reports so I can get all the details….

….

….

Hmm, I’m not finding any published research studies. I wonder why that is….

As a clinician, my patients are my primary concern. For that reason I have not conducted controlled studies where one group of patients receives treatment and another group, for comparison, receives a placebo. I cannot in good conscience deny treatment to suffering animals who I know will benefit from that treatment.

Please realize that my clinical studies have not been accepted by my peers.

Oh, there aren’t any controlled studies, published or unpublished. By “clinical studies” he means “in my personal experience.” The theoretical foundation of Plechner’s Syndrome and the evaluation of clinical efficacy of its treatment is empirical. In other words, he made it all up!

An examination of the articles and information on Dr. Plechner’s web site reveals that he invented the entire theory and decided he was right based entirely on clinical experience and anecdotes. He has neither the inclination nor the training to conduct controlled scientific research, so his claims are purely faith based. He quotes numbers and percentages, but there is no evidence that these are based on anything more than his own imagination.

It is often pointed out, quite rightly, that science doesn’t know everything, and our understanding of phenomena as complex as living organisms is likely to always be incomplete. However, the incompleteness of knowledge is not the same thing as total ignorance, nor does it mean that absolutely anything can be true. We don’t entirely understand how gravity works at the subatomic level, but that doesn’t mean we can simply imagine ourselves into a real ability to fly if we leap off a tall building.

Endocrinology, the study of glands and hormones, is an enormous field with huge amounts of highly detailed knowledge based on centuries of scientific study. While we don’t know everything, Dr. Plechner’s theory is fundamentally inconsistent with what we do know and so is highly unlikely to be true. Perhaps through pure imagination, study, and uncontrolled personal experience, one man has discovered a fundamental principle of endocrinology that will overturn decades, even centuries of established science. Or, perhaps he is mistaken. Which seems the more likely?

Beyond the fundamental implausibility of his theory and the complete absence of any pre-clinical or clinical trial research to support it, Dr. Plechner’s claims raise many of the red flags of quackery.

  1. The Galileo Complex: As already pointed out, his characterization of himself as a misunderstood visionary ahead of his time qualifies as a manifestation of the Galileo Complex.
  2. The David and Goliath Myth, and the Dan Brown Gambit: Dr. Plechner appears to believe that the medical profession is deliberately resisting his ideas out of selfish and venal motives:

How would you feel if you found out that they’ve discovered a cure for cancer but they’re not going to let anyone know about it? I’m sure you’re all responding to this question by attacking it. “Why would they do that?” “That makes no sense!” “What about the money they could make?”

I could answer all of your objections by stating a single fact. The profits that a cancer cure would accrue wouldn’t even come close to the profits made by all of the cancer treatment drugs and the associated services involved in treating cancer. Sad to say, the treatment of cancer has proven itself to be, a tremendously successful revenue builder. Why wouldn’t you keep a possible cure under wraps?

But of course, this is purely a hypothetical question. We couldn’t possibly believe that our medical institutions could be callously driven by the pursuit of profit. Why, they’re as ethical as our great financial institutions are and look at how successful they’ve been.

The frightening fact is that a cancer cure could prove to be financially disastrous to the pharmaceutical and all of the other dependent medical industries.

The One True Cause of Disease: He believes his insight explains many apparently unrelated conditions with a single, simple answer that all other doctors and scientists have somehow overlooked.

Remember, many healthcare professionals will treat the EFFECTS of the illness or disease, but not the ROOT CAUSE cause of it.

It is no longer enough to say that my Veterinarian or Health Care Professional did the best that they could. There is another way. You as a pet owner or as a patient need to DECIDE FOR YOURSELF if you or your pet want to be just another statistic.

PLECHNER’S SYNDROME ADDRESSES AND TREATS THE ROOT CAUSES OF CATASTROPHIC ILLNESSES AND NOT JUST THE MEDICAL EFFECTS. It has the potential to help millions of animal or human patients to realize their dreams of better health and greater longevity.

Other Red Flags from Dr. Walt’s List:
Is the product or practice promoted as a “Major Breakthrough,” “Revolutionary,” “Magic,” or “Miraculous”?

Is only anecdotal or testimonial evidence used to support claims of effectiveness?

Is the treatment said to be effective for a wide variety of unrelated physiological problems?

Is the product a quick and easy fix for a complicated and frustrating condition?

Is the treatment said to be effective for a wide variety of unrelated physiological problems?

Is the product a quick and easy fix for a complicated and frustrating condition?

Who Is This Guy?

While I don’t believe personal details about someone are key to evaluating the legitimacy of their scientific claims, they can be informative, particularly after the claims have clearly failed the tests of plausibility and scientific evidence and contain so many red flags of nonsense. Dr. Plechner provides a brief biography on his web site. In it, he discusses a number of dramatic experiences with the medical profession which might be expected to generate some suspicion of mainstream medicine:

1. One afternoon, when I was just seven years old, I was playing in the alley behind our house when a car came speeding up the alley and then ran over my four-year-old sister. The next door neighbors were both physicians and were home at the time. They rushed out and wrapped up my little sister in a blanket and headed straight to the nearest hospital. The interns and residents at the hospital were in a meeting at the time and were, “too busy” to attend to her massive head trauma. By the time we reached the next hospital, she had died .What a sad example for a seven-year-old child to suddenly realize that taking the, “Hippocratic Oath” must mean that you are a, HIPPOCRITE. Can you imagine what must have gone through my child’s mind seeing a hospital who did not care if a little girl died or not? 

2. One afternoon, when I was eleven-years-old, my Dad had gone to the hospital for an injection of a bronchiole dialator for his asthma called, “Aminophyline”. He suffered from a horrible allergic reaction and died within a few minutes.

3. After five years of hard work I then applied to medical school. I had hoped that just maybe I could help stop those unnecessary tragedies that befell my Dad and little sister.

At the end of my first year in medical school, I developed a horrible upset gut. The Dean of Men attributed my problem to, “freshman nerves”. After losing forty pounds, and a lot of my hair, and after being given two weeks of Paragoric, I looked at myself in the mirror and said, “self, you are going to die”. I went to see the Dean of Men the next morning, and I was so dehydrated that I spoke with a, “clicking sound”. He said to me that I could go into Public Health because it would be much less stressful…I looked like I had just come from a Concentration Camp.

I went to see my physician who with serum titers and my clinical symptoms diagnosed me with typhoid fever. My physician was livid that this, “Third World” disease could have been missed in a “high powered medical school”?

He also describes how he came to “discover” Plechner’s Syndrome. His mother was treated surgically for breast cancer, including removal of her adrenal glands and ovaries. She was on steroid replacement therapy, and Dr. Plechner’s independent reading convinced him she needed thyroid hormone supplementation. He convinced her doctor to provide this and took her subsequent good health as proof of his theories.

Is It Safe?

Since there is no research data whatsoever concerning the diagnosis and treatment of Plechner’s Syndrome, it is impossible to directly evaluate the risks of this approach. However, the glucocorticoids and thyroid hormone supplements Dr. Plechner recommend have well-recognized and potential serious side effects. While he claims that such side-effects will not occur at the doses and with the particular combinations of drugs he recommends, it must be remembered that the physiological arguments for why this is are not consistent with what the rest of the scientific community believes is the way the endocrine system works, and there is no controlled scientific evidence to show the disease he is treating even exists or that the treatment is safe or effective.

Using real drugs to treat a quite likely imaginary disorder is not a sensible way to care for our pets and our patients. While these drugs often make pets look or feel better in the short term, regardless of whether the imagined “imbalance” exists, this comes at the price of both risk from the drugs themselves and the risk of ignoring, masking, or simply overlooking  other real, and possibly treatable, disorders.

Bottom Line

Plechner’s Syndrome is an implausible hypothesis that conflicts with well-established scientific understanding of endocrinology. There is absolutely no supporting scientific data showing this theoretical disorder exists or that the proposed treatment is effective. Dr. Plechner is content with anecdotes, testimonials, and his own belief as sufficient evidence for his claims and has no intention of testing them through controlled scientific investigation. Most veterinary scientists, who generally prefer research data to storytelling, do not accept his claims.

Dr. Plechner, of course, feels this is due mostly to the veterinary profession’s fear that if his miracle cure is real it will lead to fewer sick patients and less income for veterinarians. This ridiculous and offensive suggestion is just one of many warning signs that he is promoting nonsense.

Dr. Plechner undoubtedly believes, genuinely and fervently, that he has “discovered” an important cause of disease that the rest of the scientific and medical professions have overlooked or suppressed, and he has convinced some clients and even other veterinarians of his claim. However, in the absence of any legitimate or compelling scientific evidence, despite apparently miraculous results, his treatment has not been accepted by the rest of the veterinary profession.

Just as there is no scientific evidence that Plechner’s Syndrome exists or that the proposed treatment for it works, there is no evidence to allow us to judge the safety of the approach. Using real drugs to treat a quite likely imaginary disorder is not a sensible way to care for our pets and our patients.

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Acupuncture–Not for the Faint of Heart

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Univ. of Tennessee Veterinary School Recognizes “Excellence” in Alternative Medicine

The University of Tennessee School of Veterinary Medicine is one of the most noticeable academic institutions that appears to have been co-opted for the promotion of pseudoscientific veterinary medicine (along with Louisiana State and the University of Florida). I have written previously about the Integrative Medicine program at UT and the $10,000 grant the college received from the American Holistic Veterinary Medical Foundation (AHVMF) explicitly for promoting (not studying) alternative therapies. Now, the university has presented its Distinguished Alumni award to two self-proclaimed “holistic” veterinarians. And these doctors were not honored despite their promotion of mystical pseudoscience but specifically because of it:

Dr. Marc Smith of Natchez Trace Veterinary Services and Dr. Casey Damron of White Oak Animal Hospital were recently honored with the “2012 Distinguished Alumni” Award at UT College of Veterinary Medicine in Knoxville, TN, for the creation of Pet-Tao Pet Foods and their service in the field of Alternative Veterinary Medicine.

Curious as to what about the creation of a pet food company might have merited such an award, I took a look at the Pet-Tao Foods web site. It is unashamedly dedicated to an approach to veterinary nutrition and health founded in the mystical nonsense of so-called Traditional Chinese Veterinary Medicine (TCVM). 

Our diets are truly “holistic” because each and every ingredient is chosen according to two Eastern theories that define the term “holistic” – Yin/ Yang and The Five element theory. No other pet food company has this unique perspective, experience, or credibility.

The theory [of TCVM] states that all naturally occurring events in the universe have two opposite aspects: male & female, up & down, hot & cold, dark & light. These opposing aspects are interdependent, dynamic and constantly struggling to maintain balance with each other…Food is a powerful determinant in the body’s struggle to maintain health and the balance of Yin and Yang.

In Traditional Chinese Veterinary Medicine, the five element theory explains the intricate relationships between the five naturally occurring elements in the environment: Metal, Water, Wood, Fire and Earth…When using this theory in regard to foods, one can control how organs function in the body.  For example, a geriatric dog with increased liver enzymes should be fed LIVER according to the 5 element theory. Feeding liver promotes liver function and healing while re-establishing balance of the liver with respect to other organs.

In keeping with this fanciful and completely unscientific approach to nutrition, the company does not produce foods for specific nutritional needs or medical conditions as understood in scientific medicine, but for balancing Yin & Yang and the Five Elements. This allows them to recommend a limited set of diets for any medical conditions regardless of the cause or the specific nutritional composition of the diet based entirely on their assessment of the degree of imbalance in these mystical principles identified in a TCVM evaluation (which is itself a complex and completely subjective evaluation of the tongue, the pulse, and other physical and historical factors according to rules based entirely on tradition and trial-and-error). The company’s diets include:

  • Harmony (Balanced) – No health problems, IBD.
  • Chill (Yin Diet) – Yin deficiency, panting, pacing at night, restlessness, cool seeking, hot environments, over-energetic dogs.
  • Zing (Blood Diet) – Blood deficiency, dry flaky skin, cracked dry footpads, anemia.
  • Blaze (Qi Diet) – Qi deficiency, tires Easily, warm seeking, chronic diarrhea, cold environments.
  • Soothe – Limited ingredient cooling diet.

It is probably unnecessary to point out that there is no scientific evidence to support the practice of selecting food ingredients to balance Yin/Yang or the Five Elements. This is an entirely mythological folk model similar, and likely historically related, to the Greek system of Humoral Medicine that led to the now mostly abandoned practices of bloodletting, purging, and other methods of  “balancing” the vital humours to manage health and disease.

The fact that veterinarians who are thoroughly trained in scientific medicine and who are often, at least in my experience, practicing perfectly competent science-based medicine, are able to believe in such nonsense and use it in their clinical work is a bit of an embarrassment to the profession. However, the fact that a mainstream university research and teaching institution sees the promotion of such mystical anachronisms as worthy of lauding with an award for “excellence” is much worse. This lends a thoroughly undeserved aura of legitimacy to ideas that belong on the rubbish heap of medical history along with the treatment of infection by bloodletting and of epilepsy by application of leeches.

 

 

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Chiropractic–The More Research We Do, The Less Reason There is to Believe it Works

In my previous articles about chiropractic, including a recent review of veterinary spinal manipulation for Science-Based Medicine, I have acknowledged that despite the nonsense of the theory behind chiropractic (the non-existent “vertebral subluxation”), there is at least some evidence in humans that it can be as useful for lower back pain as conventional therapies. However, some reviews have questioned whether the effect seen is clinically meaningful. Now, in an apparent example of the Decline Effect in action, the latest Cochrane review update has further downgraded the effects of chiropractic from statistically but not clinically significant to non-existent.

Rubinstein SM, Terwee CB, Assendelft WJ, de Boer MR, van Tulder MW. Spinal manipulative therapy for acute low back pain: an update of the Cochrane review. Spine (Phila Pa 1976). 2013 Feb 1;38(3):E158-77.

This review added 26 research studies involving over 2600 patients to the studies previously reviewed. Of these, 6 studies (30%) were at low risk of bias based on the quality of their execution. Spinal manipulative therapy (SMT, i.e. chiropractic) was compared with fake chiropractic, other inert placebo therapies, and other therapies thought to be beneficial for acute lower back pain as both the primary and an added (adjunct) therapy. The review concluded:

SMT is no more effective for acute low back pain than inert interventions, sham SMT or as adjunct therapy. SMT also seems to be no better than other recommended therapies.

In other words, when all the studies done are taken together, there is no evidence chiropractic has a benefit for acute lower back pain. Any other therapy, including placebos known to have no effects at all, is just as good.

The authors, as always, acknowledged that many of the studies were of poor quality, and they suggested that further high-quality research could affect this conclusion. But despite decades of intensive study, and widespread use, chiropractic is still unable to demonstrate its value for even the most plausible and seemingly appropriate use, treating back pain. The more evidence we collect, the less reason there is to believe this therapy is worth trying.

Posted in Chiropractic | 44 Comments

Benefits and Risks of Neutering–An Evidence-Based Approach

In 2010 I published an extensive narrative review of the research concerning the benefits and risks of neutering. Since then, there has been a proliferation of studies and reviews attempting to refine and strengthen the evidence and allow better individualized recommendations about neutering individual pets. I have collected my original review and links to articles updating the evidence on this subject here, and I will endeavor to keep this collection updated as more and better evidence is available on this complex and important subject.

As a general practice veterinarian, I think this subject provides a perfect example of the process of evidence-based medicine. Using the totality of the available evidence, with critical appraisal and an awareness of the limitations of each study and review, veterinarians can make informed recommendations to clients about the care of individual pets.

A one-size-fits-all policy about neutering can never be optimal as the particular risks and benefits of this procedure depend on many factors: the breed, age, size, health status, and purpose of the pet; the values, behaviors, and socioeconomic status of the owner; the independent risks for specific health problems that might also be associated with neuter status; the time and place in which the pet lives; and the availability and utilization of preventative and therapeutic veterinary care.  

Science makes the care we provide better, but it may not always make it simpler or easier. Individualization of care requires as comprehensive an understanding as possible about the real factors that influence health and disease. We cannot simply make up systems of diagnosis and therapy, such as those of homeopathy and so-called Traditional Chinese Veterinary Medicine, and then claim that we are providing individualized care if we have not validated the specific diagnostic and therapeutic methods we are using through controlled scientific research.

Conversely, we must make decisions based on the evidence we have, not the evidence we want. This means we have to be honest about what we know and don’t know, and we have to accept that there will always be significant uncertainty about the outcome in any individual case. Science can reduce this uncertainty but cannot eliminate it. And we must make the best effort possible to integrate all the complex and conflicting information available into as rational and evidence-based a recommendation as possible, rather than relying on simply, reflexive rules (such as always neuter before 6 months of age or never neuter until after 1 year of age) or the traditional but weak foundations of clinical experience and the advice of our teachers and mentors.

**In 2014, I updated my 2010 review, with the addition of scientific reports published in the intervening years. This led to a number of changes in my conclusions with regard to specific issues. The new version is available here, and while I will keep the link active to the previous version, this update supersedes the older version.

Benefits & Risks of Neutering Dogs and Cats

1) McKenzie, B. Evaluating the benefits and risks of neutering dogs and cats. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 2010 5, No. 045

2) Beauvais W, Cardwell JM, Brodbelt DC.The effect of neutering on the risk of urinary incontinence in bitches – a systematic review. J Small Anim Pract. 2012 Apr;53(4):198-204.

SkeptVet review of The effect of neutering on the risk of urinary incontinence in bitches- a systematic review

3) Beauvais W, Cardwell JM, Brodbelt DC. The effect of neutering on the risk of mammary tumours in dogs–a systematic review.J Small Anim Pract. 2012 Jun;53(6):314-22.

SkeptVet review of The effect of neutering on the risk of mammary tumours in dogs- a systematic review

4) Torres de la Riva G, Hart BL, Farver TB, Oberbauer AM, Messam LLM, et al. (2013) Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers. PLoS ONE 8(2): e55937. doi:10.1371/journal.pone.0055937

SkeptVet review of Neutering dogs: Effects on joint disorders and cancers in golden retreivers

5) Hoffman JM, Creevy KE, Promislow DEL (2013) Reproductive Capability Is Associated with Lifespan and Cause of Death in Companion Dogs. PLoS ONE 8(4): e61082. doi:10.1371/journal.pone.0061082

SkeptVet review of Reproductive capability is associated with lifespan and cause of death in companion dogs

6) Lefebvre, SL. Yang, M. Wang, M. Elliott, DA. Buff, PR. Lund, EM. Effect of age at gonadectomy on the probability of dogs becoming overweight. Journal of the American Veterinary Medical Association. 2013;243(2):236-43.

SkeptVet review of Effects of age at gonadectomy on the probability of dogs becoming overweight.

7) Zink, MC. Farhoodly, P. Elser, SE. Ruffini, LD. Gibbons, TA. Riegr, RH. Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas. J. Amer Vet Med Assoc. 2014;244(3):309-319.

SkeptVet Review of Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas.

8) Hart BL, Hart LA, Thigpen AP, Willits NH. Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers. PLoS ONE 2014;9(7): e102241. doi:10.1371/journal.pone.0102241

Sketpvet Review of Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers.

9) O’Neill DG, Church DB, McGreevy PD, Thomson PC, Brodbelt DC. Longevity and mortality of cats attending primary care veterinary practices in England. J Feline Med Surg. 2015 Feb;17(2):125-33. doi: 10.1177/1098612X14536176. Epub 2014 Jun 12.

SkeptVet Review of Longevity and mortality of cats attending primary care veterinary practices in England.

10) M.M.E. Larsen, B. Børresen, A.T. Kristensen.  Neuter status and risk of cancer in a Danish dog population. 

SkeptVet Review of Neuter status and risk of cancer in a Danish dog population.

What is a Spay: Ovariectomy Versus Ovariohysterectomy forFemale Dogs

11) Salas Y, Márquez A, Diaz D, Romero L (2015) Epidemiological Study of Mammary Tumors in Female Dogs Diagnosed during the Period 2002-2012: A Growing Animal Health Problem. PLoS ONE 10(5): e0127381. doi:10.1371/journal.pone.0127381

SkeptVet Review of  Epidemiological Study of Mammary Tumors in Female Dogs Diagnosed during the Period 2002-2012: A Growing Animal Health Problem.

12) Graf R.  et al. Swiss Feline Cancer Registry 1965-2008: the Influence of Sex, Breed and Age on Tumour Types and Tumour Locations. J Compar Pathol. 2016.

Neutering and Cancer Risk in Cats

13) Hart, B. L., Hart, L. A., Thigpen, A. P. and Willits, N. H. (2016). Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence. Veterinary Medicine and Scienc. doi: 10.1002/vms3.34

SkeptVet review of Neutering of German Shepherd Dogs

14) Sundberg CR. Belanger JM. Bannasch DL. et al. Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study. BMC Veterinary research. 2016;12:278.

SkeptVet review of Gonadectomy and Immune Disorders

15) New Report on Complication Rates of Neutering in Dogs and Cats

16) Neutered Dogs Liver Longer than Intact Dogs

17) New Evidence about When to Neuter Your Dog

Posted in Topic-Based Summaries | 26 Comments

Benefits and Risks of Neutering, An Evidence Update: Effects of Neutering on Longevity and Cause of Death in Dogs

Another new study has recently been published addressing the complex issue of the risks and benefits of neutering dogs. This report certainly will not answer all the outstanding questions or quiet the debate about when and if to neuter dogs, but it does add some useful information.

Hoffman JM, Creevy KE, Promislow DEL (2013) Reproductive Capability Is Associated with Lifespan and Cause of Death in Companion Dogs. PLoS ONE 8(4): e61082. doi:10.1371/journal.pone.0061082

The Study
The study was a retrospective analysis of records from the Veterinary Medical Database (VMDB). This is a collection of medical records from veterinary school teaching hospitals going back to 1964. The authors pulled all records in this database for dogs seen at participating hopsitals between 1984 and 2004, a total of over 80,000 records. They excluded individuals with missing information about relevant variables (such as neuter status, age at death, and so on). The final analyses involved over 40,000 records. Slightly over half of the subjects were neutered, and slight less than half were intact at the time of death (56.4% and 43.6% respectively).

Results
Life Span
Overall, males lived about 14% longer when neutered, and females lived about 26% longer when neutered. From the Kaplan-Meier plots presented, it appears differences were less after about 12 years of age. This is interesting in light of the reports of another study, on Rottweilers, that suggested exceptional longevity was more likely in animals not neutered or neutered later in life. It may be that those individuals who achieve exceptional longevity are different from those who do not in ways that outweigh any effect of neutering on longevity, and thus they may not be an appropriate population in which to study the effect of neutering on life span.

Cause of Death
The table below shows the odds ratios for sterilized males and females compared to intact dogs for specific categories of causes of death. 

Causes of Death for Neutered Dogs

Sterilized dogs were significantly less likely to die from infection, trauma, degenerative disease and vascular disease. They were significantly more likely to die from immune-mediated disease and cancer. Most of these differences held for both males and females and when the effect of age was accounted for, meaning that sterilized and intact dogs did not die from different causes simply because they died at different ages.

Specific cancers were examined if they occurred in more than 1% of the total population. Sterilized dogs were at greater risk for death from all of these eight types of cancer except mammary cancer, supporting the notion that neutering in females is protective against this disease.

It is important to remember that these are relative differences in risk. Other studies have shown that the incidence of mammary cancer may be much higher than of the others, such as lymphoma and osteosarcoma, and that breed plays a role. So if neutering is protective against a very common cancer and increases the risk of a very rare cancer, overall it may still be safer to be neutered than not. That is why overall life expectancy information is relevant as well. It makes sense to perform an intervention that raises the risk of a rare disease if most patients still live longer because they are protected against a common disease.

Several specific infectious diseases occurred with sufficient frequency to be analyzed individually. Sterilized dogs were at lower risk of death due to four of these five disease. However, these results are a bit more problematic than those concerning cancer risk. Unlike most cancers, the parasitic and infectious diseases listed are almost all completely preventable with proper vaccination or other preventative veterinary care. This raises the question of whether differences between sterilized and intact animals in these causes of death may be confounded by differences in the level of care they receive, in the socioeconomic status of their owners, in the time and place in which they lived, and many other variables not specifically addressed in this study.  

It is interesting that the same patterns in differences between cause of death in neutered and intact dogs were seen across many different breeds, each with their own specific risk pattern for particular diseases. Cancer, for example, appeared to be a more common cause of death in neutered compared to intact animals even in breeds with relatively low rates of cancer. This strengthens the idea that neutering is directly associated with the risk of such disease and also emphasizes the importance of considering the absolute, rather than relative risk, and the overall risk picture in any individual patient.

Limitations
There are a number of significant imitations to this study. As already mentioned, there are many potential confounding variables not addressed, including the time and place where subjects lived, the overall level of veterinary care they received, the socioeconomic status of their owners, the purpose for which the dogs were owned (work, companionship, breeding, etc), and many others.

In particular, the higher risk of preventable causes of death in sterilized dogs might be simply a reflection of less aggressive preventative veterinary care in these patients. However, studies in humans and in mice have suggested that infectious disease risk is lower in neutered individuals in the absence of differences in environment, resources, or preventative healthcare, so there may be a true biological relationship at work as well.

The authors also acknowledge that lack of information about the age at neutering and previous reproductive activity is a significant limitation. And it is understood that patients at university veterinary hospitals are often representative of a very different population than those seen in general practice, so the applicability of these results to the general dog population may be problematic.

Nevertheless, this study has a number of strengths and cannot simply be dismissed. The size of the population and the ability to correct cause of death for age and breed are particularly important in identifying real general associations between neutering and health that can be further investigated. Comparisons between this population and dogs in Europe, where neutering is uncommon, would be particularly useful in establishing the specific effects of neutering on disease risk for both males and females across a range of breeds, sizes, and lifestyles.

As I have often said, I believe it is a good thing we are questioning the established dogma about universal early neutering, which is based on pretty limited evidence, I think it would be unfortunate, however, to replace it with another dogma on the basis of, as yet, no better evidence. I suspect a siple rule that can easily be applied in all cases (always neuter, never neuter, neuter before/after Age X, etc) is never going to be reliable because physiology is simply more complex and nuanced than that. Recommendations about neutering any specific individual will have to take into account the overall picture of risks and benefits based on age, sex, breed, size, life circumstances, and other variables. As always, we must try to tailor our recommendations to the specific needs of individual patients using the best available evidence to inform, but not blindly dictate, what we recommend.

Posted in Science-Based Veterinary Medicine | 16 Comments

From Science-Based Medicine–Veterinary Chiropractic

People are sometimes surprised to learn that all the heavy hitters of alternative medicine, such as acupuncture, chiropractic, homeopathy, etc., are inflicted on animals as well as humans. I’ve written about veterinary homeopathy, and the associated manufactroversyin a previous post, and today I thought I’d take a look at veterinary chiropractic.

The Players

In most states, chiropractic is defined in terms of treatment of humans and chiropractors are thereby licensed only to treat humans. However, there are a variety of ways around this for people who want to subject their animals to this therapy. Some chiropractors will simply treat animals and ignore the fact that it isn’t technically legal for them to do so. And some veterinarians will take one of the many training courses available in animal chiropractic and then employ it as part of their practice of veterinary medicine. A previous SBM article has discussed the lack of consistency or legitimate scientific content in most of these courses.

State veterinary practice acts will also sometimes create legal space for animal chiropractic, often under another name, which avoids the jurisdictional problem of calling it chiropractic when that term is usually legally defined specifically with reference to humans. In California, for example, the practice of “musculoskeletal manipulation” on animals must meet certain requirements specific in the state veterinary practice act:

  1. A veterinarian must examine the animal, determine that musculoskeletal manipulation (MSM) is appropriate and safe, and take official responsibility for supervising the treatment.
  2. Then the owner is supposed to sign a form: “The veterinarian shall obtain as part of the patient’s permanent record, a signed acknowledgment from the owner of the patient or his or her authorized representative that MSM is considered to be an alternative (nonstandard) veterinary therapy.”
  3. Then a licensed chiropractor can examine the pet, determine that MSM is appropriate, and then consult with the supervising vet before performing treatment.

I know of many chiropractors treating animals in the state, with and without veterinary supervision. I have never seen anyone follow these rules.

The perceived legitimacy of veterinary chiropractic is bolstered by the activities of professional veterinary chiropractic organizations, such as the American Veterinary Chiropractic Association (AVCA). This group offers a certification program which allows either chiropractors or veterinarians to claim to be board-certified in animal chiropractic, despite the technicality that the American Board of Veterinary Specialties, which credentials specialty boards, does not recognize this certification and thus it is essentially a fake board certification.

The International Veterinary Chiropractic Association (IVCA), based in Europe, is largely indistinguishable from the AVCA in terms of the content and general approach to promoting animal chiropractic and certifying chiropractors, including the lack of recognition of their specialty certification by the European Board of Veterinary Specialisation (EBVS).

These groups are not to be confused with the International Association of Veterinary Chiropractitioners (IAVC), a group of veterinarians, chiropractors, and apparently any other kind of “health care provider” who cares to join, who fix subluxations with methods difficult to distinguish from chiropractic but who claim to be practicing an entirely original form of therapy called Veterinary Orthopedic Manipulation (VOM) and who prefer to be referred to by the proprietary term “chiropractitioner.” They do share, however, the lack of any formal recognition as a legitimate specialty that characterizes the work of the AVCA and the IVCA.

And then, of course, there are all the individual chiropractors and veterinarians practicing some form of manual therapy based on chiropractic, often with their own idiosyncratic theories and techniques. For example, Dr. Hall recently drew my attention to a book called “Like Chiropractic for Elephants” by Norman “Rod” Block D.C. Dr. Block claims to have “an uncanny touch sensory perception that allows him to connect with the person or animal he comes in contact with…It is then that the animal senses his intention of wanting to help and releases inhibitions that allow discovery of where the root cause of the pain, stress or pressure may exist…The doctor uses his uncanny ability to tune into the root cause of animal states of disease without the use of drugs or surgery.”

I confess I have not been able to stomach paying to read Dr. Block’s book, but thanks to his press release and a few reviews, I have at least a small sense of what it offers. Apparently Dr. Block supplements his understanding of the vertebral subluxation and his “uncanny” sensory abilities with the practice of “Quantum Shamanetics.” In this method, “The quantum shamanist learns to trust and be guided by universal wisdom that exists beyond our genetic blueprint. By being part to, and observing, movement, one becomes more sensitive to subtle changes in energy. By following these dynamic changes, the shamanist develops a more expansive relationship with the flow of life and health.”

Sadly, this is not a unique case of a chiropractor leaving the at least marginally plausible terrain of treating musculoskeletal disease in animals and venturing further afield. Last year, I had the opportunity to evaluate the recommendations of Dr. Steven Eisen, a chiropractor who calls himself a “Holistic Dog Cancer Expert” and has a book and series of web videos explaining how to thwart the mischief of incompetent veterinarians and treat canine cancer with his dietary advice and a dedicated avoidance of vaccines and parasite control products. And perhaps not surprisingly, Dr. Eisen did not exhibit the scientific spirit of respect for open inquiry and debate when challenged for his claims. Instead, he threatened to sue me.

What Is Animal Chiropractic?

For the most part, the principles and practices of animal chiropractic are extrapolated and adapted from those applied to humans, despite the obvious biomechanical and anatomic differences between bipedal hominids and quadrupedal veterinary patients. As in human chiropractic, the core concept behind chiropractic for animals is the subluxation, or the vertebral subluxation complex (VSC). The AVCA criteria for certification includes familiarity with, “the anatomical, biomechanical and physiological consequences of the Vertebral Subluxation Complex,” and the organization suggests that in addition to pain and musculoskeletal disorders, treatment of the VSC can be beneficial for “bowel, bladder, and internal medicine disorders…glands and body functions.”

Veterinary journal articles about chiropractic often emphasize that the subluxation “is at the core of chiropractic theory, and it’s detection and correction are central to chiropractic practice.”(1) They then include lengthy, very impressive and sciency descriptions of how subluxations arise, cause disease, and can be treated. These are usually marred only by the small problem that no one has actually been able to show a subluxation exists in any species despite over a century of trying.(2)

Chiropractors working on humans cannot reliably agree on the location of a supposed subluxation despite extensive and involved theoretical and practical training supposedly intended to help them do so.(3-4) You can’t see it on x-rays, it doesn’t pinch nerves, and as the evidence for subluxations as physical abnormalities has failed to materialize, true believers in chiropractic have gone through amazing intellectual contortions to redefine it in ways that can make it sound real while still being undetectable. A dragon in the garage if there ever was one.

What’s the Evidence?

There is at least some reasonable evidence that spinal manipulations such as practiced by chiropractors may benefit humans with back pain, though Cochrane reviews of spinal manipulation and general chiropractic therapy for even this indication find small effects and research with a high risk of bias. There is no good reason to believe chiropractic is useful for any other complaint in humans.

Reviewing the literature on the effects of veterinary chiropractic care is quite easy since there is almost none. A search of the PubMed and VetMed Resource databases identified no controlled clinical trials of chiropractic therapy in any veterinary species.

Apart from a few case reports, there are several studies evaluating the putative effect of spinal manipulations on sensitivity to painful stimulus and on spine and limb movement in horses.(5-7) These papers suffer from significant limitations and risk of bias. They generally show a lack of adequate randomization and blinding, objective outcome measures and control groups. They frequently measure numerous variables of questionable clinical significance and then ignore the majority that show no change while identifying the few that do show statistically significant differences as somehow indicative of a meaningful treatment effect. While they represent a reasonable attempt to identify criteria for evaluating the effects of spinal manipulation on horses, they do not constitute evidence of efficacy for chiropractic therapy for any disease.

Of course, there is the usual mountain of testimonials and anecdotes which suggest miraculous curative results with chiropractic therapy in animals. These are both unreliable, for all the usual reasons, and unfortunately the most compelling kind of evidence for animal owners

What’s the Harm?

The risks of chiropractic care in humans fall into the usual categories for harm from alternative therapies; direct harm from the treatment and indirect harm associated with irrational belief systems and avoidance of truly effective care. Of the adverse effects documented in humans, the most significant is that of strokes associated with cervical manipulation.(8) There is no research evaluating the direct risks of veterinary chiropractic, so we can only speculate on the safety of spinal manipulation for animal patients.

The indirect risks of chiropractic therapy come from being exposed to irrational fear of science-based medicine and the use of other unproven or clearly ineffective alternative treatments. Chiropractors treating humans, for example, are often inclined to recommend against vaccination, and it is not uncommon for them to employ therapies far less plausible than chiropractic, such as colon cleansing, homeopathy, and many others.

Chiropractors practicing on animals have also been known to stir up irrational fear of vaccination, claim toxins in pet food are common causes of cancer, and otherwise express disdain for science-based veterinary medicine. And a look at the sponsors for the ACVA annual conference illustrates the frequently close relationship between animal chiropractors and practitioners of other alternative therapies such as Traditional Chinese Veterinary Medicine, Standard Process Supplements, Reiki and homeopathy, and others. Such synergy between chiropractic and other alternative therapies has the potential to harm veterinary patients even if direct spinal manipulation does not.

Since anecdotes are so commonly employed in defense of veterinary chiropractic, I feel justified in sharing one illustrating its risks. I was once asked to examine a rabbit that had come to my hospital to be treated by a chiropractor, at the advice of another veterinarian. The rabbit had been anesthetized for treatment of dental disease earlier in the day and upon waking was paralyzed in its hind legs. Even a cursory familiarity with rabbit medicine would immediately lead one to consider a fracture or dislocation of a lumbar vertebrae since these can happen when rabbits kick their powerful hind legs uncontrollably, and rabbits are susceptible to disorientation and panic when emerging from anesthesia.

The chiropractor had already examined the rabbit and concluded it had a subluxation in its cervical spine. He recommended giving a chiropractic adjustment to the neck and sending the pet home, with additional adjustments likely necessary in the following days or weeks. When I asked how he reconciled his diagnosis with the symptoms, which fit the classic pattern associated with a spinal cord injury in the lower back, the chiropractor informed me that he was familiar with “allopathic” neurology textbooks but had chosen to ignore them because they were not consistent with his daily experience in practice.

The client permitted me to take an x-ray which confirmed a traumatic lumbar vertebral fracture and severe spinal cord trauma. The patient was humanely euthanized in light of the severe symptoms and poor prognosis. Though this was sad, I consider it a better outcome for the animal than having its neck twisted and being sent home paralyzed and with a fractured spine but without any pain control, as the chiropractor had recommended. Granted, such a story cannot prove anything about the safety or efficacy of animal chiropractic therapy, but it is at least illustrative of some of the risks of substituting a pseudoscientific belief system for science-based medicine.

Bottom Line

Though there is no reliable data, the popularity of chiropractic for treatment of humans appears to translate, to at least some extent, to the treatment of animals. The fundamental theories and practices of animal chiropractic are copied or extrapolated from those employed in treating humans, however there is virtually no reliable scientific evidence to show any benefit from veterinary chiropractic treatment. There is also no controlled evidence identifying the risks of chiropractic therapy of animals, so we can only speculate about the safety of this intervention. It is clear, however, that chiropractic therapy for animals is often associated with opposition to conventional medical care and with other unproven or clearly ineffective alternative therapies, and this presents some risks to patients seeking care from so-called animal chiropractors.

References

  1. Maler, MM. Overview of veterinary chiropractic and its use in pediatric exotic patients. Vet Clin Exot Anim. 2012;15:299-310
  2. Miritz TA. Morgan L. Wyatt LH. Greene L. An epidemiological examination of the subluxation construct using Hill’s criteria of causation. Chiropr Osteopat 2009;2:17-13.
  3. French SD, Green S, Forbes A. Reliability of chiropractic methods commonly used to detect manipulable lesions in patients with chronic low-back pain. J Manipulative Physiol Ther. 2000 May;23(4):231-8.
  4. Hestbaek L, Leboeuf-Yde C. Are chiropractic tests for the lumbo-pelvic spine reliable and valid? A systematic critical literature review. J Manipulative Physiol Ther. 2000 May;23(4):258-75.
  5. Haussler, KK. Martin, CE. Hill, AE. Efficacy of spinal manipulation and mobilisation on trunk flexibility and stiffness in horses: a randomised clinical trial. Equine Veterinary Journal. 2010; 48 (Supp. 38):695-702.
  6. Gomez Alvarez, CB. L’Ami, JJ. Moffatt, D. van Weeren, PR. Effect of chiropractic manipulations on the kinematics of back and limbs in horses with clinically diagnosed back problems. Equine Veterinary Journal. 2008;40(2):153-159.
  7. Sullivan, KA. Hill, AE. Haussler, KK. The effect of chiropractic, massage and phenylbutazone on spinal mechanical nociceptive thresholds in horses without clinical signs. Equine Veterinary Journal. 2008;40(1):14-20.
  8. Ernst, E. Adverse effects of spinal manipulation: a systematic review. J R Soc Med July 2007 vol. 100 no. 7 330-338
Posted in Chiropractic | 19 Comments

Intravenous Vitamin C for Cancer Treatment in Pets

Introduction
Vitamin C (also known as ascorbic acid) is a micronutrient found in many foods. Interestingly, it is essential for primates and guinea pigs, but not for any other mammals since most species can manufacture it from other substances in their diets. The discovery that the disease scurvy, common throughout history among sailors and others without access to fresh fruits and vegetables for long periods, was due to Vitamin C deficiency is one of the classic examples of early use of science and scientific methods to solve a serious health problem. Ensuring adequate Vitamin C intake has been one of the most effective public health measures in history.

However, in the 1970s the notion began to gain popularity that extremely high doses of Vitamin C, well beyond any nutritional requirements, could be used as a drug to prevent or treat disease. This was largely due to the efforts of Nobel Laureate Linus Pauling, a brilliant chemist who developed a bit of an obsession with the medicinal use of Vitamin C in his later years. Because of this, he is considered the paragon of the Nobel Disease, in which an accomplished scientist becomes enamored of implausible or pseudoscientific ideas and refuses to abandon them when the evidence dictates they should. Though the verdict is not etched in stone on all aspects of the medicinal use of megadoses of Vitamin C, but as we will see it is clear that Pauling suffered from the Nobel Disease with respect to this practice.

The two primary uses to which Pauling, and many others in his time and since, have suggest Vitamin C could be put are in the prevention and treatment of the common cold and cancer. In terms of the common cold, the evidence indicates there is no benefit for prevention and there might or might not be a small, largely clinically irrelevant benefit for treatment. Pauling was unquestionably wrong on this one. The situation is more complex with regard to cancer therapy.

Does It Work?
The initial studies of Vitamin C as a cancer therapy, reported by Pauling and Dr. Ewan Cameron, appeared to show a benefit in terms of survival when cancer patients received large doses of Vitamin C along with standard therapy. However, these were methodologically terrible studies that were likely only accepted for publication on the basis of Pauling’s prestige. Subsequent research by others replicating this work (e.g. 1, 2) did not find any benefit. A nice review of this history is available on the Science-Based Medicine Blog.

One objection to the negative studies offered by proponents of Vitamin C as a cancer therapy was that they primarily gave the vitamin orally. There is some in vitro and lab animal evidence (e.g. 3, 4) suggesting Vitamin C is more toxic to cancer cells than healthy cells at very high doses (though, of course, there are some limitations to these studies). The concentrations associated with this effect can only be achieved in living animals with intravenous injection of high doses of Vitamin C, so some have argued that the studies showing no benefit from oral use should be re-evaluated with intravenous dosing.

There is little clinical research in humans, and none in companion animals, to show that intravenous high-dose Vitamin C is beneficial for cancer patients.  Some small scale uncontrolled studies and case reports have shown some potential effects, but it is unclear if there is any meaningful benefit in terms of survival, quality of life, and other clinically important variables. A narrative review from 2010 concludes:

In view of this lack of data after trials which have included at least 1,591 patients over 33 years, we have to conclude that we still do not know whether Vitamin C has any clinically significant antitumor activity. Nor do we know which histological types of cancers, if any, are susceptible to this agent. Finally, we don’t know what the recommended dose of Vitamin C is, if there is indeed such a dose, that can produce an anti-tumor response.

Similarly, the American Cancer Society position on Vitamin C in cancer patients states,

Although high doses of vitamin C have been suggested as a cancer treatment, the available evidence from clinical trials has not shown any benefit.

And while it is easy, as always, to find supportive anecdotes, it is also easy to find anecdotes that show no benefit. I’ve discussed previously why such anecdotes are only useful in suggesting, not proving, hypotheses. Unfortunately, anecdotal evidence is a bit like a two-headed coin in that proponents of any practice win no matter which side is showing. If a patient seems to improve, that is claimed to demonstrate the therapy works. If a patient doesn’t improve, however, that doesn’t indicate that the therapy doesn’t work in general, only that it doesn’t work in all patients. Since nothing is perfect, this sounds reasonable until you realize that with this kind of spin anecdotes can only ever be used to support a therapy, never to challenge it.

The most positive possible spin one can put on the evidence in humans and lab animals is that there might be a small benefit in some cases, though it is more likely this is simply random noise in the data produced by a small number of studies with significant limitations. No spin at all can be put on the evidence for intravenous Vitamin C in companion animals because there is none, apart from the inevitable anecdotes, of course. One study has shown intravenous Vitamin C generates high levels of the chemical in dogs for only a very short time, so any beenfits would either have to happen from only a brief period of exposure or many injections would have to be given frequently to have any effect.

Is It Safe?
I have always argued that any therapy which has a benefit will undoubtedly have side effects. Living organisms are simply too complex to tinker with their workings and not have unintended, as well as desirable, effects. Though its benefits are still unproven, there is no doubt megadoses of Vitamin C have real physiological effects, and so there is the possibility for harm as well as benefits.

Some research conducted about the same time as Pauling’s studies has suggested that dietary Vitamin C can accelerate the growth of some cancers in laboratory mice. Minor side effects are commonly reported, including nausea, diarrhea, and changes in blood pressure and blood sugar.

And high doses of Vitamin C given intravenously have been documented to cause kidney failure, so it should not be used in patients with any compromise in kidney function. Formation of kidney stones has also been linked to Vitamin C supplementation. Individuals with certain enzyme deficiencies or abnormalities of iron absorption can also be harmed by excessive Vitamin C supplementation. A particularly significant issue in cancer patients is that Vitamin C has been shown to reduce the effectiveness of some anti-cancer drugs. Using a chemical with unproven value that can interfere with the proven benefits of medication in patients with a serious disease is not smart or compassionate care.

Once again, there doesn’t appear to be any formal scientific research on the safety of high doses of intravenous Vitamin C in companion animals. Using such a therapy is a bit like throwing darts blind-folded and hoping to hit the bull’s eye rather than the person standing next to the target.

Bottom Line
High doses of Vitamin C given by intravenous injection have not been proven to have any benefit in human cancer patients. There are some studies suggesting such a benefit might exist, but the evidence is weak and contradictory. There is also evidence of both minor and serious side effects associated with this treatment. Vitamin C can interfere with some chemotherapy drugs, thus reducing the benefits of conventional therapy. And, as always, there is a serious risk of harm for patients who elect this unproven therapy over better studied treatments with known risks and benefits.

There is no published clinical research in companion animals evaluating the effects of intravenous Vitamin C as a cancer therapy. The safety and efficacy of this practice is completely unknown despite claims made based on uncontrolled anecdotes and extrapolation from studies in humans.

Posted in Herbs and Supplements, Miscellaneous CAVM | 51 Comments

Discussion of Homeopathy Continues in the AVMA

Over the last few months, I have followed the progress of a resolution introduced to the American Veterinary Medical Association House of Delegates identifying homeopathy as an ineffective therapy incompatible with evidence-based medicine. The story can be traced through several articles describing the resolution, delineating the evidence on which it is based, and critically evaluating the response and arguments put forward by defenders of homeopathy:

AVMA Considers Resolution Acknowledging Homeopathy is Ineffective

Growing Support for the AVMA Resolution Declaring that Homeopathy is Ineffective

The Evidence for Homeopathy-A Close Look

What “Experts” in Homeopathy are Supposed to Believe

Response to Comments from the American Holistic Veterinary Medical Association on the Homeopathy Resolution

There have also been a series of letters to the editor of the Journal of the American Veterinary Medical Association (JAVMA) talking about the resolution and the issues it raises as well as more generally about CAVM. Unfortunately, JAVMA is not an open access journal, so only subscribers can access these links (in order from oldest to most recent). However, I thought it might be helpful to have links to the discussion collected in one place for the sake of those interested and able to access the journal:

http://avmajournals.avma.org/doi/pdf/10.2460/javma.241.7.864

http://avmajournals.avma.org/doi/pdf/10.2460/javma.241.9.1146

http://avmajournals.avma.org/doi/pdf/10.2460/javma.241.9.1146

http://avmajournals.avma.org/doi/pdf/10.2460/javma.241.12.1560

http://avmajournals.avma.org/doi/pdf/10.2460/javma.242.2.153

http://avmajournals.avma.org/doi/pdf/10.2460/javma.242.3.307

http://avmajournals.avma.org/doi/pdf/10.2460/javma.242.8.1046

The most recent letters concerned reported comments by Dr. Douglas Aspros, AVMA President, and Dr. Kenneth Bartels, House Advisory Committee Vice Chair. Both opposed the resolution not on scientific grounds but on the basis of political considerations and a clear misunderstanding of the intent and the issues involved. One response to their comments attempted to clarify these issues so that the debate about homeopathy can stay focused on what is important: the way in which therapies are evaluated, ideally through rigorous scientific research, and the importance of adhering to this standard in order to protect the welfare of patients. This letter had to be rather drastically edited to be acceptable to JAVMA, which is not surprising considering it is quite critical of the AVMA leadership, but hopefully it still provides a useful perspective:

As a supporter of the AVMA House of Delegates resolution identifying homeopathy as ineffective, of course I was disappointed it was not adopted. I appreciate the intentions of those who opposed the resolution, and I believe that most are smart people who care about the welfare of their patients. However, I also believe that, as stated in the materials supporting the resolution, homeopathy is no more than a placebo. If this is so, then using homeopathy without informing clients of this would be unethical; good intentions alone cannot legitimize homeopathy if it is not effective.

Even though the resolution was not adopted, it did accomplish one of its purposes, which was to initiate a discussion of the scientific and ethical issues concerning homeopathy. The evidence and arguments of both sides are now available for all to evaluate. Unfortunately, recent comments reported in the JAVMA News article on the resolution could be interpreted as mischaracterizing both the resolution and the intent of those proposing it.

For example, the news report summarized AVMA President Douglas Aspros’ comments as arguing that the resolution “is divisive without benefit to the AVMA or AVMA members, and he hopes the AVMA will avoid considering such resolutions in the future” and that “passage of the resolution wouldn’t stop anyone from practicing homeopathy or change the opinions of those who hate homeopathy.” Dr. Kenneth E. Bartels, the House Advisory Committee vice chair, reportedly objected to the resolution because, in the words of the reporters, it “could put the AVMA on a slippery slope toward examining many other modalities such as acupuncture, low-level laser therapy, and chiropractic care.”

To me, these comments suggest a belief that the resolution was motivated by emotion (“hate” of homeopathy), was intended to change the opinions of homeopaths or prevent them from practicing homeopathy, and should not have been offered because it was divisive and might lead to the critical evaluation of other alternative therapies. If accurate, such comments misrepresent the purpose of the resolution and imply priorities I find troubling.

It is inappropriate to suggest the purpose of the resolution was anything other than generating a productive discussion about an important issue and protecting the interests of patients and clients. I do not hate homeopathy, I simply view it as ineffective and unsafe.

I also believe the AVMA should act in the interests of the public and our patients even if this risks offending some members. We cannot meet our ethical obligations as medical professionals if we prohibit debate on important scientific and ethical questions simply because some might not welcome such a debate.

Finally, the principles of evidence-based medicine require that all medical therapies be subject to critical evaluation on an ongoing basis. Shielding certain therapies from the scientific evaluation conventional practices undergo as a matter of course, solely because they are identified as complementary or alternative, is not in the best interests of our clients or patients.

Posted in Homeopathy | 8 Comments