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Veterinary Joint Supplements-Glucosamine & Chondroitin

Posted on June 5, 2009 by skeptvet

What is it?

Osteoarthritis (OA), also called degenerative joint disease (DJD), is a common and painful disease in older humans and animals. OA mostly affects cartilage, the hard but slippery tissue that covers the ends of bones where they meet to form a joint. Healthy cartilage allows bones to glide over one another with little friction. It also absorbs energy from the shock of physical movement.

In osteoarthritis, the surface layer of cartilage breaks down and wears away, exposing the underlying bone. Bone rubbing against bone causes pain, and leads to inflammation, a complex response which contributes to further cartilage loss and discomfort. Over time, small deposits of bone – called osteophytes or bone spurs – may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space. This causes more still more pain and damage.

Because animals cannot directly inform their caretakers of mild discomfort, the first signs of OA in veterinary patients are usually lameness and a reluctance to engage in normal activities. By the time such signs are noticed, the condition has usually progressed to moderate or severe disease. A diagnosis of OA usually requires a physical examination by a veterinarian, who can identify subtle signs of pain, osteophytes, and reduced range of joint motion. X-rays can also help identify DJD, though these are not always reliable indicators of discomfort or function.

The primary treatments for humans and animals with OA are weight loss, regular moderate exercise, and pain medications, typically the non-steroidal anti-inflammatory drugs (NSAIDs). There has also been interest among some health care providers in so-called nutraceuticals- substances derived from food sources that might treat the symptoms or alter the progression of OA.

Glucosamine is a substance found in joint cartilage and joint fluid. It is normally produced by the body from basic ingredients in food, and some is incorporated into joints. Though glucosamine is only one of the many building blocks of cartilage, it has been theorized that supplementing glucosamine orally might stimulate production or repair of cartilage. Some researchers have also suggested glucosamine might reduce inflammation in arthritic joints and thus reduce discomfort and slow the progression of the disease. Most supplement forms of glucosamine are derived from shellfish.

Chondroitin sulfate is another normal constituent of cartilage, and it has also been theorized to reduce inflammation and cartilage degradation in OA and perhaps to slow progression and improve comfort. Chondroitin in supplements is usually derived from cow cartilage.

Since glucosamine and chondroitin are categorized as nutritional supplements, they are not regulated by the Food and Drug Administration. Manufacturers do not have to prove that they are safe or effective in treating OA, and they do not have to abide by the strict quality control requirements for the production of approved drugs. Independent testing of over-the-counter glucosamine and chondroitin products have shown that they vary greatly in composition, and many do not actually contain the ingredients indicated on the label. Therefore, even if the substances have a role in treatment of OA, there is some concern that the actual preparations sold for humans and animals may not be of any value simply because they may not contain much of the ingredients.

Does It Work?

There has been a great deal of research on the effects of glucosamine and chondroitin on cells from joint tissues isolated in the laboratory. Though the results are inconsistent, some studies do show a number of actions on cells that might suggest a use for these agents in patients with OA, so the theory behind their use is plausible. However, there are other reasons for questioning whether these agents could actually work in a real patient.

For example, some controversy about whether oral preparations of chondroitin sulfate, which is a very large and electrically charged molecule, can be absorbed into the body and whether it actually get into joints affected with OA. Results of studies on the availability of oral glucosamine and chondroitin are extremely inconsistent, but generally show a low level of absorption in humans, rats, dogs, and horses. While some of the absorbed molecules do appear to reach affected joints, it is not clear if the amount is sufficient to have any effects. The amount that reaches the joints when the products are given orally is generally less than the amount used in the laboratory to demonstrate possibly useful actions on isolated cells and much less than the amount of glucosamine already circulating in the animal’s body.

Extensive clinical trials have been conducted in humans to determine if glucosamine and chondroitin can reduce symptoms or slow progression of OA. The best quality scientific studies require blinding, where the patients and researchers do not know whether each subject is getting the real treatment or a fake (placebo) treatment. And many other factors complicate interpretation of human clinical trials, so confidence in the results can only come from consistent, repeatable outcomes of numerous well-designed trials conducted by different investigators.

The results of these clinical trials are also highly inconsistent. In general, older studies with small numbers of patients and funded by supplement manufacturers showed some benefit from oral glucosamine and chondroitin. However, as larger, independently-funded trials with more subjects and better design have been published, the evidence has become predominantly negative.

The largest and best trial so far is the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), a study comparing glucosamine and chondroitin, separately and together, against placebo and an NSAID (celecoxib, or Celebrex). Overall, the NSAID improved comfort and function significantly more than the placebo, while the various glucosamine and chondroitin products did not. Another study of many of the same subjects over 2 years did not find any significant difference in loss of joint space on x-rays (a measure of progression of OA) compared to the placebo. On balance, then, the evidence in humans suggests little to no benefit of these agents on symptoms or progression of OA.

There is very little research on the use of glucosamine and chondroitin in OA for veterinary patients. A recent review found only one good quality study comparing a combination glucosmine/chondroitin product to NSAIDs and placebo in dogs. In this study, the NSAIDs showed significant benefit on both objective and subjective measures of pain compared with placebo, but there was no difference between the placebo and the nutraceutical product.

Therefore, though there are some interesting effects of chondroitin and glucosamine on joint tissue in the lab, there are also questions about whether they could be effective in real patients. The balance of the clinical research evidence in both humans and animals does not suggest there is any real benefit of oral supplementation of these agents in patients with osteoarthritis.

Is It Safe?

Oral glucosamine and chondroitin supplements appear to be safe. There is some possibility that they may interfere with platelets, an element in the process of blood clotting. Alone, this does not seem to be of any clinical significance, but it is recommended that they not be used in patients already on anti-coagulant medications such as aspirin, clopidogrel (Plavix), or heparin.

There are also some concerns about glucosamine interfering with treatment for diabetes since it is structurally similar to sugar. In humans, this does not appear to be a real risk for diabetic patients. There is no research on this issue in veterinary patients.

Summary

Ø Glucosamine and chondroitin appear to have effects on joint tissues isolated in the laboratory that might indicate they could be useful adjuncts to osteoarthritis treatment if these effects also occurred in patients given oral preparations of these substances. However, there are reasons to question whether they could have such effects because they are poorly absorbed, and little of what is taken orally actually reaches affected joints.

Ø In humans, the largest and best clinical trials studying oral glucosamine and chondroitin supplements shows little to no effect on pain or on the degeneration of cartilage in patients with osteoarthritis.

Ø There is virtually no good quality research on the use of glucosamine and chondroitin in veterinary patients. The best study so far, done in dogs, found a combination of these agents to be of no benefit for patients with osteoarthritis. Further research in animals with osteoarthritis is warranted, but at this time the evidence does not support the use of glucosamine and chondroitin in these patients.

Ø Glucosamine and chondroitin taken orally appear to be safe in veterinary patients. However, they should not be taken by patients on anti-coagulant medications, and they should be used with caution in diabetics.

Ø The best treatments for osteoarthritis in veterinary patients, as in humans, are maintenance of a healthy weight, regular moderate exercise, and non-steroidal anti-inflammatory medications for pain

References and More Information

Aragon, C.L., Hofmeister, E.H., Budsberg, S.C., Systematic review of clinical trials of treatments for osteoarthritis in dogs. J Am Vet Med Assoc 2007; Feb 15;230(4):514-21.

Barker Bausell, R., Snake Oil Science: The Truth About Complementary and Alternative Medicine, Oxford University Press, 2007

Clegg, D.O., et al. Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis. N Engl J Med. 2006 Feb; 23;354(8):795-808.

Goggs, R., et al. Nutraceutical Therapies for Degenerative Joint Diseases:

A Critical Review. Crit Rev Food Sci Nutr 2005;45:145–164

Moreau, M., et al. Clinical evaluation of a nutraceutical, carprofen, and meloxicam for the treatment of dogs with osteoarthritis. Vet Rec 2003; 152:323-329

National Institute of Health, National Institute of Arthritis and Musculoskeletal and Skin Diseases. Handout on Health: Osteoarthritis 2006. http://www.niams.nih.gov/Health_Info/Osteoarthritis/osteoarthritis_hoh.pdf

Neil, K.M., Caron, J.P., Orth, M.W. The role of glucosamine and chondroitin sulfate in treatment for and prevention of osteoarthritis in animals. JAVMA Apr 2005;226(7);1079-1088

Sawitzke, A.D. The effect of glucosamine and/or chondroitin sulfate on the progression of knee osteoarthritis: A report from the glucosamine/chondroitin arthritis intervention trial. Arthritis Rheum 2008 Oct;58(10):3183-91

The Cochrane Collaboration, The Cochrane Reviews, a searchable database of systematic reviews of the human medical literature at http://www.cochrane.org/reviews/

Posted in Herbs and Supplements | 27 Comments

Veterinary Probiotics

Posted on June 5, 2009 by skeptvet

What is it?

A widely used definition of probiotics is “Live microbes that, when administered in adequate amounts, confer a health benefit on the host.” The basic idea is that all animals have a great number and variety of microorganisms living in and on their bodies, and that many of these microbes are commensuals, organisms that benefit from living on the host and that in return convey some benefit to the animal. Such benefits include inhibiting disease-causing organisms from colonizing the host, producing nutrients for the host, and possibly participating in the normal development and regulation of the immune system. Animals raised in laboratories without any colonizing microbes, and animals with abnormal numbers and types of microbes, often experience disease, so it is believed that an appropriate microbial ecology is important for normal health and function.

Though many organisms have been used, most probiotic products contain bacteria, often from the Bifidobacteria or Lactobacillus groups, or Saccharomyces (brewer’s yeast). While some of the bacteria suggested as probiotics are natural parts of the gut ecology, many strains are not, and brewer’s yeast of course does not normally live in or on animals.

To be potentially useful, a probiotic organism must not normally be capable of causing disease (though many are opportunistic pathogens, able to cause disease under certain circumstances). It must be able to survive the acidic environment of the stomach and at least temporarily survive in the intestines, where most normal bacterial flora is found. Typically, probiotic organisms do not colonize individual animals well and must be taken continuously to be present in any number. Finally, a probiotic preparation must contain enough live organisms in an appropriate delivery vehicle to enable colonization of the intestines.

While the scientific principles behind probiotics are sound, there are a number of problems with the practical use of such preparations. Every individual animal has a complex ecology of microbes colonizing it, and the specific type and number depend on species, environment, community, and individual genetics. Even for humans, as many as 80% of the organisms we harbor have yet to be identified or studied, and much less is know about the microbial ecology of companion animals. So trying to manipulate this ecology and the health of the individual by adding a few bacteria, often of a strain not naturally found in the individual, may not make sense. Also, numerous tests have shown that commercial probiotic products often do not contain the organism they claim, they are sometimes contaminated with undesirable organisms, and they may have too few microbes or non-living microbes in them. Without any formal government regulation or monitoring it is difficult to know whether individual products are safe or effective.

Does It Work?

Much laboratory research has been done on many different potential probiotics, and there is good evidence to support the principle that such organisms can influence health and disease. Clinical studies in humans, however, have often produced mixed or disappointing results.

Based on clinical trials in humans, the balance of the evidence supports the effectiveness of some probiotic preparations for prevention and treatment of diarrhea caused by antibiotics, infection, or radiation treatment and for treatment of lactose intolerance. There is also good evidence for their use in irritable bowel syndrome and some other inflammatory gastrointestinal tract diseases. The evidence is inconclusive for most uses of probiotics, including in preventing or treating traveller’s diarrhea, urinary tract infections, fatty liver syndrome, and Helicobacter infections responsible for stomach ulcers. Research evidence does not support the use of probiotics in Crohn’s disease, ulcerative colitis, asthma, allergic eczema, or rheumatoid arthritis.

Further research may find other potential benefits from probiotics, but because the composition and function of the normal microbial ecology is so poorly understood, it is not yet clear which conditions may benefit from the use of which organisms. At this time clinical studies are largely based on haphazard selection of products and conditions rather than on strong, plausible scientific hypotheses.

While there has been extensive research on the effect of probitics in livestock, there are very few published studies on their use in companion animals. Studies in horses have shown poor colonization of human-derived organisms. Several trials have failed to show any benefit of probiotics on the shedding of disease-causing organisms such as Salmonella. One small study suggested some benefit from brewer’s yeast in treatment of diarrhea, although the duration o hospitalization and the overall outcome was not affected by the treatment.

In dogs, human-derived organisms are also ineffective at colonizing the intestines. Dog-derived microbes do seem to reach and survive in the intestines, but no clinical for these has yet been demonstrated. And in cats, there are no published research studies on the use of probiotics for prevention or treatment of disease.

The marketing literature accompanying veterinary commercial products often claims safety and efficacy based on company studies or other unpublished research. While these findings are interesting, it has been clearly shown that industry-sponsored research is more likely than independant research to find results in favor of the product being tested. In addition, such marketing materials deliberately avoid any research that does not favor the product, so while useful such materials cannot be relied upon exclusively to decide if a product is safe or effective.

Is It Safe?

There are very few reports of disease or harm caused by probiotics. Individuals with ineffective immune systems (such as the elderly, pregnant women, people with HIV or receiving chemotherapy) are at increased risk of disease from all microbes, and there have been cases of severe illness caused by bacterial or yeast infections from probiotic products given to the patient or to others in their hospital unit. Very sick or immunocompromised individuals should not use these products. Interestingly, however, newborns and infants have often been subjects in studies of probiotics, and the majority show no adverse effects.

Some probiotic organisms are closely related to disease-causing microbes. Enterococcus faecium is a widely available veterinary probiotic related to other members of the Enteroccocus group, which commonly cause serious infections. Such organisms have the potential to cause illness or to share genes for antibiotic resistance with other, disease-causing members of the same group.

Some risks from probiotics are related to their intended functions, to interact with the microbial flora and affect the immune system. In horses, one study of a probiotic given to prevent diarrhea found the product actually caused diarrheal illness is neonatal foals. A study in dogs showed the probitoic Enterococcus faecium potentially improved the attachment to the intestines of the disease-causing organism Campylobacter. And other studies have shown some inflammatory conditions, such as allergic rhinitis, can increase in people given probiotics for another condition. So while the balance of the evidence is that these products are quite safe, because they do have real effects on the body they can potentially have unintended or undesirable effects.

Summary

Ø A normal microbial flora is beneficial, and perturbations in the normal flora are associated with disease, so the principle that manipulating the microbial ecology can affect health is reasonable.

Ø The normal microbial flora is complex and poorly understood, so how to appropriately manipulate it to achieve health benefits is not yet clear.

Ø Clinical studies in humans are mixed, showing benefits from some probiotic products for some conditions, no benefit in other cases, and inconclusive results for many products and conditions.

Ø There is little reliable research in companion animals regarding the safety or efficacy of probiotic products.

Ø The risks of probiotics are probably very low. Individuals with compromised immune systems are at greatest risk and should not be exposed to probiotics. There is some limited potential for these products to cause disease even in healthy individuals.

References and More Information

The Cochrane Collaboration, The Cochrane Reviews, a searchable database of systematic reviews of the human medical literature at http://www.cochrane.org/reviews/

Crislip, M. Probiotics. Science-Based Medicine Blog. http://www.sciencebasedmedicine.org/?p=344#more-344

FAO/WHO. Guidelines for the evaluation of probiotics in food. http://www.who.int/foodsafety/fs_management/en/probiotic_guidelines.pdf

Rice, L.B., et al. Transferable, Plasmid-Mediated VanB-Type Glycopeptide Resistance in Enterococcus faecium. Antimicorbial Agents and Chemotherapy 1998 April; 42(4): 963–964

Rinkinen, M., et al. Interaction between probiotic lactic acid bacteria and canine enteric pathogens: a risk factor for intestinal Enterococcus faecium colonization? Vet Microbiol 92: 111-119

Versalovic, J., Wilson, M., Eds. Therapeutic Microbiology: Probiotics and Related Strategies, ASM Press, Washington, DC, 2008

Weese, J.S. Microbiologic evaluation of commercial probiotics. JAVMA 2002; 220(6): 794-797

Weese, J.S., Rousseau, J. Evaluation of Lacotbacilluc pentosus WE7 for prevention of diarrhea in neonatal foals. JAVMA 2005; 226(12): 2031-2034

Wynn, S.G. Probiotics in veterinary practice. JAVMA 2009; 234(5): 606-613

Posted in Herbs and Supplements | 9 Comments

Raw Diets for Dogs and Cats

Posted on June 5, 2009 by skeptvet

What’s All the Fuss About?

Pet owners are naturally concerned about providing the best care for their pets, and no form of care is more direct and meaningful that what we feed our animal companions. Rare but serious problems with contamination of commercial foods for dogs and cats have stimulated significant anxiety about the safety of these foods and generated increased interest in alternatives. One such alternative is a variety raw diets, often referred to as BARF (Bones and Raw Food) diets. Even some veterinarians have suggested these diets may be beneficial to our canine and feline pets. Unfortunately, there are many myths surrounding these diets, and the facts don’t support their use.

Myth 1: Dogs and cats are carnivores and evolved to eat uncooked whole prey.

Dogs have been domesticated for tens of thousands of years, and they have been eating human leftovers for the vast majority of that time. There are significant physical and genetic differences between dogs and their closest wild relative, the wolf, and the genetic evidence suggests they diverged into separate species close to 100,000 years ago. The teeth and gastrointestinal tract of dogs has adapted to the human food they have eaten for so long. We have also made many changes in our canine companions through breeding. There is little resemblance between the average Chihuahua and a wolf, and little logic to the idea that they should have the same diet.

Cats, on the other hand, have remained hunters despite their associations with humans, and their nutritional needs are closer to those of their wild ancestors. Nevertheless, they too have been much changed by human intervention, and there are still significant differences between domestic and wild cats which make a pure prey diet less than ideal.

It is also important to point out that wolves and other wild carnivores generally live longer in captivity when fed cooked commercial diets, and the nutritional advisory group for American zoos recommends these diets over raw, whole prey for captive carnivores. And while cats often do hunt and eat whole prey, they also suffer from infections, parasites, and other illnesses related to eating birds and rodents. Raw whole prey is clearly not a natural diet for dogs. And it is not at all clear that raw prey is the healthiest or optimal food even for cats or other carnivores for which it is a natural diet.

Myth 2: Uncooked food is more nutritious than cooked commercial diets.

Proponents of BARF diets sometimes claim that vitamins and other nutrients are destroyed by cooking and so raw diets are more nutritious than cooked ones. While it is true that cooking reduces the amounts of some nutrients, it also makes others more available and easier to absorb. And while cooked commercial diets are designed to have adequate levels of vital nutrients in the final product, most raw and homemade diets tested have been found to be nutritionally unbalanced or inadequate. A number of case reports have been published of pets who developed diseases of malnutrition when fed BARF or other homemade, raw diets.

Myth 3: Raw diets are safer than commercial foods.

The recent tragedy involving melamine contamination of commercial pet foods has caused much anxiety about the safety of these products. It is important to remember, however, that such events are very rare, especially considering the tens of thousands of pets eating these diets for decades. Still, if raw diets were truly safer that would be a powerful reason to consider feeding them.

Unfortunately, there are many dangers to raw diets. Raw bones are frequently part of such diets, and these often cause fractured teeth and gastrointestinal upset, and they have been responsible for deaths from tears in the stomach and intestines.

Many raw diets tested have been shown to contain potentially deadly bacteria, including Salmonella, E. coli, and Clostridium. Dogs and cats have been shown to shed these bacteria after eating raw diets, potentially exposing other pets and humans to them, and cases of illness and death from contaminated raw meat have been published. Proper handling and cooking of raw meat can greatly reduce the risk of such bacterial infections. And contrary to the claims of some BARF proponents, there is no evidence that dogs or cats are naturally protected or immune to these infectious agents.

Intestinal parasites are very common in wild carnivores, and uncooked meat is a significant source of these. One study has shown a significant increase in parasitic disease in dogs fed homemade raw diets. The facts about such risks make it clear that overall raw diets are not safer than cooked commercial diets.

Myth 4: Raw diets are healthier than processed commercial diets.

There is no evidence to support claims that dogs or cats are healthier when fed raw diets rather than balanced commercial foods. With dramatic improvements in nutrition and healthcare and the reduction of infectious disease, parasitism, and trauma as causes of death over the last few decades, our pets are living longer than ever before. Some advocates of raw diets have pointed to an increase in deaths from cancer among companion animals as evidence commercial diets are unhealthy. However, it is far more likely that the better quality of nutrition commercial diets provide has increased the lifespan of our pets, and that cancer is more common because it is a disease of aging and there are now more elderly pets than there used to be.

As already pointed out, eating raw diets increases the risk of intestinal parasites and infections. Such diets are often not nutritionally adequate or balanced and this can lead to diseases of malnutrition. Despite the claims of many proponents, there is no reason to believe BARF diets are healthier, or even as healthy, as conventional cooked diets.

Summary

Ø While there is no evidence that raw diets benefit our pets, there are clear risks to feeding them. Though there are many myths suggesting these diets are superior to cooked commercial pet foods, the facts do not support this.

Ø In addition to the risks to our pets, there are potential risks to humans from feeding raw pet diets. The Food and Drug Administration (FDA) warns that raw pet foods can increase people’s exposure to disease-causing organisms, such as Salmonell, E. coli, and intestinal parasites. This is an especially significant concern for those most vulnerable, including children, pregnant women, the elderly, and people with depressed immune systems from HIV infection or immunosuppressive drug therapy. While additional studies are being done, at this point the evidence does not support any benefit to raw diets that might outweigh the risks.

References and More Information

Chengapappa, M., et al. Prevalence of Salmonella in raw meat diets used in racing greyhounds. J Vet Diag Invest 1993;5:372-7.

Finley, R. et al. The risk of Salmonella shedding by dogs fed Salmonella-contaminated commercial raw food diets. Can Vet J 2007;8:69-75.

Food and Drug Administration, Center for Veterinary Medicine, Pet Food webpage, http://www.fda.gov/cvm/petfoods.htm

Freeman L., Michel, K., Nutritional analysis of 5 types of “Raw Food Diets.” JAVMA March, 2001;218(5): 705.

Joffe, D., Schlesinger, D. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Can Vet J 2002;43:441-442.

Lauren , S., et al, Computer analysis of nutrient sufficiency of published home-cooked diets for dogs and cats. Proc ACVIM Forum 2005.

Nutritional Advisory Group, American Zoo and Aquarium Association, http://www.nagonline.net/husbandry_chapters.htm#W

Rahman, A., Yathiral, S., Commercial Vs. Traditional Food In Canine Health Poster/Abstract at – Waltham International Nutritional Science Symposium – Innovations in Companion Animal Nutrition Abstracts, Washington DC, USA September 15-18, 2005

Robinson JGA, Gorrel C. The oral status of a pack of foxhounds fed a “natural” diet (abstract). Proceedings. Fifth World Veterinary Dental Congress. Birmingham, England, 1997.

Weese, J. et al. Bacteriological evaluation of commercial canine and feline raw diets. Can Vet J 2005;46:513–516.

Stiver, S. et al. Septicemic salmonellosis in two cats fed a raw meat diet. J AM Anim Hosp Assoc 2003;39:538-42.

Strohmeyer, R.A., et al., Evaluation of bacterial and protozoal contamination of commercially-available raw meat diets for dogs. JAVMA 2006;228:537-542.

Posted in Nutrition | 1 Comment

Veterinary Homeopathy

Posted on June 5, 2009 by skeptvet

What is it?

Homeopathy was invented in the late 18^th and early 19^th century by Samuel Hahnemann. While there is some variations in specific homeopathic practices, the fundamental system invented by Hahnemann is still the basis for modern homeopathy. In a time before scientific, evidence-based medical practices, doctors frequently did more harm than good with traditional but not systematically tested therapies like bleeding, purging, and the administration of toxic substances. Hahnemann recognized the lack of success, and even active harm, of contemporary treatments and tried to create an alternative.

He first came up with the so-called Law of Similars. This principle states that something which causes certain symptoms in a healthy person should be able to relieve those symptoms in a sick person. Hahnemann’s apparent basis for this idea was that when he or other healthy people took certain remedies used in his era to treat specific diseases, the healthy subjects seemed to develop symptoms similar to the disease the remedy was supposed to treat. No consistent evidence has ever been found to support this idea that like cures like. Furthermore, modern testing of agents used in some homeopathic remedies has not confirmed that they even cause the symptoms they are believed by homeopaths to cause.

Hahnemann reasoned that giving sick people substances which caused signs of illness in healthy people would probably do harm, so he decided these substances should be greatly diluted before being used as remedies. He even became convinced that the more one diluted a substance, the greater its curative power. Homeopathic remedies are generally diluted many hundred or thousands of times, and it has been clearly shown that most no longer contain even a single molecule of the original material used to make them. Homeopathic practitioners do not dispute this, but they claim that the water (or sometimes alcohol) used for dilution retains some mysterious memory of the substance and so can be used as a cure. Again, no reliable evidence exists that dilution strengthens a substance’s curative properties or that water retains a memory of something that it no longer contains.

Finally, Hahnemann believed that to make his diluted remedies truly effective, they had to be activated by succussion (vigorous shaking). This, in his words, made the substance “excited and able to act spiritually upon the vital forces.” The combined effect of dilution and succussion led, in Hahnemann’s view, to the potentization of the substance, making it an effective remedy.

Hahnemann did not believe diseases had physical causes, such as the bacteria, viruses, toxins, and other sources of illness recognized by science today. He saw diseases as ailments of the spirit rather than the body, and this idea still influences modern homeopathy. Many homeopaths dispute the very basis of science and medicine and prefer theories based on spiritual forces, mysterious undetectable energies, exotic interpretations of quantum mechanics, or semiotics. These practitioners argue that the scientific evidence against their claims is unimportant because they do not accept that scientific research is a useful way to determine if a medical therapy is safe or effective. They are frequently inconsistent in this, however, in that when they find a study which seems to support their practices, they are quick to publicize the fact.

Does It Work?

There is no reliable evidence to support the underlying concepts of homeopathy. No research has shown that like cures like, or that diluting and shaking a mixture gives it any special curative powers. Most homeopathic preparations are so dilute that even homeopaths acknowledge that no traces of the original substance used to make them can possibly remain. Numerous attempts have been made to find physical evidence for any change in the water or alcohol vehicle after dilution and succussion, but no such evidence has been found by any properly conducted, repeatable study.

The clinical studies of homeopathic treatments in human patients overwhelmingly demonstrate that such treatments are no better than a placebo. The best quality scientific studies require blinding, where the patients and researchers do not know whether each subject is getting the real treatment or a fake (placebo) treatment. And many other factors complicate interpretation of human clinical trials, so confidence in the results can only come from consistent, repeatable outcomes of numerous well-designed trials conducted by different investigators.

Multiple reviews over the last decade of the best quality studies, with reasonable numbers of subjects and good controls for bias, have found no benefit from homeopathic treatment beyond a placebo effect. Most telling is a 2005 review which compared homeopathic treatments to new, conventional pharmaceutical treatments for the same conditions. The homeopathic treatments showed marginal effects consistent with a placebo, whereas the conventional medicines showed clear, unequivocal effectiveness. This is an example why homeopathy is typically used only to treat chronic, naturally waxing and waning or self-limiting conditions with subjectively reported symptoms. Homeopathy is not generally applied to acute, life-threatening illnesses with objectively measurable signs that would not respond to a placebo treatment.

As is usually the case, the veterinary studies on homeopathy are few and of generally poor quality. While animals are not subject to the same psychological influences as human patients, the owners and veterinarians monitoring their symptoms are. The best veterinary studies of homeopathy, those that have been properly blinded or looked at objective laboratory measures of effect, have not found any benefit from homeopathic treatment.

Is it Safe?

Few direct harmful effects of homeopathic preparations have been reported. Those that are least diluted (less than 500 times) could conceivably contain traces of the original substance, and some allergic reactions to these have been seen in humans. This has not been reported in animals.

The primary danger of homeopathic treatment, however, is that it is often used in place of properly proven scientific diagnosis and treatment. This allows the disease and suffering of the patient to persist, and possibly to progress past the point where otherwise beneficial conventional treatment can be effective. And since many homeopaths reject the basic scientific explanations of disease or the legitimacy of scientific medical research, these individuals often recommend against conventional therapies, including medicines and immunization. This exposes patients to unnecessary risk and suffering.

Summary

Ø There is no evidence for the reality of the principles underlying homeopathy, such as the Law of Similars or the notion that diluting and shaking a substance gives it curative powers.

Ø The clinical research evidence in humans overwhelmingly demonstrates that homeopathic treatment is no more than a placebo, affecting a patient’s beliefs and feelings about their disease but not the disease itself.

Ø The clinical research evidence in animals is sparse and of poor quality. The best studies done to date show no benefit of homeopathic treatment.

Ø Homeopathic treatment by itself is unlikely to be harmful. However, since it has no real effect on the body and yet can create a perception of improvement in symptoms through the placebo effect, the use of homeopathy can delay legitimate scientific diagnosis and therapy, thus prolonging suffering and potentially denying the patient effective relief.

References and More Information

Barker Bausell, R., Snake Oil Science: The Truth About Complementary and Alternative Medicine, Oxford University Press, 2007

The North American Society of Homeopaths, Research and Philosophy Web Page, http://www.homeopathy.org/research.html#Philosophy

Ramey, D., Rollin, B., Complementary and Alternative Veterinary Medicine Considered, Iowa State Press, 2004

Saxton, J., Gregory, P., Textbook of Veterinary Homeopathy, Beaconsfield Publishers, 2005

Shang, A., et al., Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy. Lancet Aug-Sep 2005;366(9487):726-32

Sing, S., Ernst, E., Trick or Treatment: The Undeniable Facts About Alternative Medicine, W.W. Norton & Company, 2008

The Cochrane Collaboration, The Cochrane Reviews, a searchable database of systematic reviews of the human medical literature at http://www.cochrane.org/reviews/

Posted in Homeopathy | 2 Comments

Veterinary Chiropractic

Posted on June 5, 2009 by skeptvet

What is it?

Chiropractic is primarily the manipulation of bones in the spine in an effort to treat or prevent disease or to reduce discomfort. Though therapeutic manipulation of bones in the spine and elsewhere has a long history, chiropractic as it is understood today was invented in the late 19^th century by Daniel David Palmer. He conceived the notion that all disease results from vertebrae in the spine being out of place (so-called “subluxations”), and that forcefully manipulation of the vertebrae (an “adjustment”) can prevent or treat disease. He gave varying explanations for this idea over time, often claiming that nerves carried a spiritual energy, called “innate intelligence,” and that obstruction of the flow of this energy by vertebral subluxations caused medical symptoms. There is no reliable evidence that vertebral subluxations as Palmer described them exist or cause disease, and even some chiropractors do not believe that subluxations are real or can be detected and treated by chiropractic methods.

Nevertheless, many chiropractors, especially those that still believe in Palmer’s subluxation theories, reject modern scientific explanations of illness. It is not unusual for these practitioners to deny that infectious organisms, such as bacteria and viruses, cause disease, and they frequently recommend avoiding accepted medical prevention or treatment, such as vaccination and antibiotic therapy.

Other chiropractors have rejected the subluxation idea and the claim that manipulation of the spine can prevent or treat disease in other parts of the body. These practitioners focus on the possible usefulness of chiropractic manipulation to treat back pain only, and often recommend both chiropractic and conventional medical therapy.

There is little consistency to the kind of therapy chiropractors provide. While most forcefully manipulate the spine, there are many different techniques and much controversy in the chiropractic literature about them. Chiropractors often utilize other treatment methods as well, applying heat, cold, laser light, magnets, electrical stimulation, and topical products to the patient, and recommending other alternative treatments such as herbal products. Overall, there is no universally accepted definition of what chiropractic is, what kinds of treatments it encompasses, or what conditions it might be useful for.

Chiropractic theory and practice has been applied to animals since Palmer’s time. Despite the dramatic and obvious differences between the anatomy of the human spine and that of all other mammals, chiropractors have often asserted that subluxations occur and cause disease in veterinary patients in the same way as in humans, and they have recommended therapeutic adjustment for animals. Even many chiropractors who do not believe in subluxation theory claim to be able to identify and treat back pain and other problems in animals.

Does It Work?

Despite decades of research and the use of imaging methods such as x-rays, CT scans, and MRI, no reliable evidence for the existence of Palmer’s vertebral subluxations has been found. Studies, even in journals devoted to chiropractic, have shown that common methods for detecting subluxations are unreliable. Individual chiropractors do not consistently identify the same sites for supposed subluxations in a given patient, nor can multiple chiropractors examining the same person agree on where the patient’s problem is located. Research studies show that the identification of a specific spot in the back as the source of a problem is essentially the same as picking a location at random.

Extensive research has been done on humans for use of chiropractic treatment in many different diseases. As always, the best quality scientific studies require blinding, where the patients and researchers do not know whether each subject is getting the real treatment or a fake (placebo) treatment, and this is difficult since a patient familiar with chiropractic may be able to tell which treatment they are getting, and it is impossible to blind the person giving the treatment. Many other factors complicate interpretation of human clinical trials, so confidence in the results can only come from consistent, repeatable outcomes of numerous well-designed trials conducted by different investigators.

When the best quality studies, with reasonable numbers of subjects and good controls for bias, are reviewed they find spinal manipulation to be ineffective for almost all conditions in which it has been tested. There is some reasonable evidence that spinal manipulation does can provide mild relief for back pain (an improvement of about 10 points on a 100 point pain scale). This level of relief is no greater than that provided by conventional medical therapy such as stretching, exercise, physical therapy, and non-steroidal anti-inflammatory drugs.

As is often the case with alternative therapies, there is no high-quality research on spinal manipulation or other chiropractic therapies in animals. Only small studies with poor controls for bias and lack of objective measures of outcome have been done. At this time, any claims for the usefulness of chiropractic treatment in animals are unfounded. Significant underlying anatomical differences between humans and other mammals suggest that therapy useful only for lower back pain in humans is unlikely to be relevant to disease in our four-legged veterinary patients.

Is it Safe?

Mild side-effects, such as headache, soreness, dizziness, and numbness occur in roughly half of human chiropractic patients. Much more rare, but also much more serious events have been reported. Tears in vertebral arteries can occur following manipulation of the neck, and these have led to stroke and permanent disability or death in a number of patients. Fractures of the vertebrae and rupture of intervertebral disks have also been reported.

Many chiropractors make extensive use of x-rays despite the lack of any evidence that such imaging methods can identify subluxations or other lesions amenable to chiropractic treatment. Though the danger of a single x-ray is minimal, repeated x-rays can increase cancer risk.

Those chiropractors who oppose conventional therapies and preventatives, such as antibiotics, pain medications, and vaccines, can be responsible for unnecessary risk and suffering in their patients by discouraging the use of proven, effective medical treatment or disease prevention. And as chiropractic therapy is not useful for problems unrelated to the spine, employing such treatment for other illnesses can delay appropriate diagnosis and treatment.

Finally, since the only demonstrated benefit of spinal manipulation is relief of back pain in humans, and since this therapy is no more effective than conventional medical therapy for these symptoms, the risks posed by chiropractic therapy seem unjustified by the benefits.

No reliable research exists on the safety of chiropractic treatment for veterinary patients. Injuries to horses from chiropractic manipulations have occasionally been reported. It is likely that the risk of vertebral artery tears would be lower given the differences in anatomy of the spine. However, it is also likely that the benefits for treatment of back pain in humans would not be relevant to veterinary patients for the same reason. And the use of chiropractic in place of legitimate scientific diagnosis and treatment would present the same risks for animals as for humans.

Summary

Ø There is no compelling evidence for the reality of Palmer’s concepts of innate intelligence or vertebral subluxations. Subluxations cannot be reliably identified, and even many chiropractors no longer believe they exist.

Ø The best quality clinical research shows that spinal manipulation provides no benefit for most conditions. It can provide mild relief of back pain in humans, at best equivalent to conventional medical therapy.

Ø There is no good-quality research to suggest spinal manipulation is of benefit in animals. Significant differences in the anatomy of the spine make it questionable whether veterinary patients would experience the same causes of lower back pain as humans or that manipulative therapy would provide the same benefits.

Ø There are several mild side effects commonly associated with chiropractic treatment in people, including headache, soreness, dizziness, and numbness. There are also rare but serious risks that can lead to disability or death in humans. No reliable research evidence exists regarding the safety of chiropractic treatment in animals.

References and More Information

Barker Bausell, R., Snake Oil Science: The Truth About Complementary and Alternative Medicine, Oxford University Press, 2007

Ernst, E., Canter, P.H., A systematic review of systematic reviews of spinal manipulation. J R Soc Med 2006;99:192-6

Hestboek, L., Leboeuf-Yde, C., Are Chiropractic Tests for the Lumbo-Pelvic Spine Reliable and Valid? A Systematic Critical Literature Review. J Manip Physiolog Therap May 2000;23(4)

International Chiropractic Pediatric Association, Vaccine Information Website, http://www.icpa4kids.org/research/children/vac_info.htm

Leon-Sanchez, A., Cuetter, A., Ferrer, G., Cervical spine manipulation: an alternative medical procedure with potentially fatal complications. South Med J Feb 2007;100(2):201-3

Ramey, D., Rollin, B., Complementary and Alternative Veterinary Medicine Considered, Iowa State Press, 2004

Sing, S., Ernst, E., Trick or Treatment: The Undeniable Facts About Alternative Medicine, W.W. Norton & Company, 2008

Stevinson, C., Ernst, E., Risks associated with spinal manipulation. Am J Med May 2002;112(7):566-71

Vohra, S., et al., Adverse events associated with pediatric spinal manipulation: a systematic review. Pediatrics Jan 2007;119(1):275-83.

The Cochrane Collaboration, The Cochrane Reviews, a searchable database of systematic reviews of the human medical literature at http://www.cochrane.org/reviews/

Posted in Chiropractic | 2 Comments

What is Open-Mindendess?

Posted on June 4, 2009 by skeptvet

When discussing the evidence for and against CAM, especially with passionate believers, the issue of “open-mindedness” almost always comes up. Despite my desire to be insightful and original, I can think of no better beginning for discussing this idea than the old cliché: Always keep an open mind–but not so open that your brain falls out!

Science is dedicated to the principle of letting the facts have the final word, and so pre-judging an idea is contrary to the core philosophy of science. Any idea should stand or fall on its merits, not merely one’s feelings or a priori biases. So when I encounter a new CAM therapy, or even new evidence regarding one I am already familiar with, I approach it with an open mind. This means that even if my intuition tells me the idea is nonsense, I ask questions about the principles and I ask for evidence, for data to support that it does what the person claims it does. If this evidence is high quality (meaning well-conducted scientific research, preferably replicated randomized placebo-controlled clinical trials), then I’m on board! If the evidence is suggestive but not definitive (a plausible rationale, supportive in vitro research, perhaps some case reports), then I reserve judgment pending further study. But if the evidence is of poor quality (individual testimonials, no matter how many, proprietary research by an organization selling the product, underlying principles that violate well-established laws of nature, appeals to authority or tradition, and so on), then it moves me not!

The fundamental misunderstanding many people have about “open-mindedness” is that it means either not judging something to be true or false at all, or applying no standard of quality to the evidence used to judge the verity of a proposition. I was recently read the riot act by another doctor at my practice for being rigid and closed-minded about alternative therapies. When questioned, it turned out that what she meant was that believing scientific research is superior to anecdote, personal impressions, and cultural traditions as a form of evidence is to be closed-minded. Unfortunately, this is an example of a dangerous misunderstanding that even an extensive education in medical science does not apparently protect one against.

The history of medicine offers countless examples of why many smart people over many generations can be wrong about whether a therapy works or doesn’t work. Bloodletting, cupping, and purging are excellent examples of therapies which persisted for centuries with widespread belief in their efficacy among medical professionals and the general public but which we now know are not beneficial, and can even be harmful. The unprecedented increase in the length and quality of life for most human beings since the advent of scientific medicine is further evidence that clinical judgment and tradition are inferior to properly-conducted research in determining the validity of medical interventions. Science deserves to be taken more seriously than intuition or tradition not based on some patriarchal, ethnocentric, narrative of hegemony (as the post-modernists would have it) but because it has demonstrated its epistemological superiority in the real world, and has changed fundamentally the nature of the human experience.

Why, exactly, we trust our judgment far more than it deserves is a complex and fascinating topic. I have listed below a number of books which investigate this question, and which I have found profoundly eye(and mind)-opening. It is clear that our perceptions are heuristic, quick and dirty methods for making fast and efficient judgments that worked more often than not in the evolutionary environment that shaped our brains. But in the far more complex and ambiguous world of modern medicine, we can do better. We can do science!

The accusation of closed-mindedness leveled so often at skeptics of CAM usually carries the implication of intellectual arrogance as well. This strikes me as wonderfully ironic. To say that I as an individual, no matter how smart and well-educated and experienced, can be led astray by cognitive errors that are intrinsic to the structure and operation of my brain and so that I must rely on the processes of science above my personal feelings and judgment is arrogant. However, to assert that my personal experiences “prove” the truth of something so thoroughly that any contradictory scientific research can be dismissed is to be “open-minded.” Clearly, this makes no sense. It is a weak post hoc rationale for doing what we desperately want to do—believe we are right because we feel like we’re right.

So open-mindedness, properly understood, means judging each idea on its own merits, not on where it comes from, what other ideas it resembles, or how brilliant or foolish it makes us feel. It means getting as close to an objective, dispassionate understanding of the facts as we can and then basing our conclusions on those facts, not on our intuition or gut feelings. In short, it does not mean we should not try to judge if something is true or not but that we should base these judgments on the kind of evidence that has proven reliable before. And this means scientific evidence, not anecdote or tradition or faith.

Veterinary Joint Supplements-Glucosamine & Chondroitin

Veterinary Probiotics

Raw Diets for Dogs and Cats

Veterinary Homeopathy

Veterinary Chiropractic

What is Open-Mindendess?

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A Book from the SkeptVet

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