Duralactin for Arthritis

I was recently asked by a reader to comment on yet another product marketed for arthritis treatment in dogs and cats: Duralactin. Because arthritis is a very common disease for which there is no definitive cure, it is a popular target for commercial remedies. I have reviewed many of these, but of course there are far more out there I have not addressed. Some, like non-steroidal anti-inflammatory drugs (NSAIDs) are well-researched and their risks and benefits are clearly known. Others, like glucosamine, are quite popular despite little or no evidence of efficacy. Some, like homeopathy, are certainly useless quackery. Duralactin falls into that enormous area of remedies that have so little evidence associated with them almost nothing definitive can be said about their safety or efficacy.

What Is It?
According to the manufacturer, Duralactin is “a patented milk protein concentrate from the milk of hyperimmunized cows.” That sounds very “science-y,” but it really isn’t very revealing. Theoretically, this means the product contains antibodies extracted from the milk of cows stimulated by some means to produce those antibodies. What these antibodies are, how they were produced and processed, and of course what if anything they do for patients with arthritis is not revealed.

Does It Work?
I have not been able to find any published research evidence to answer this question. This is never a good sign. In fact, marketing a product with vague ingredients described in “science-y” language and supported primarily by anecdotes and testimonials is part of a constellation of warning signs for snake oil.

The company does refer to some in vitro experiments which suggest that injecting cows with a bacterial vaccine can stimulate production of compounds in the milk that reduce the activity of some cells involved in the inflammatory response. It is a long, long road, however, from there to a clinical therapy for arthritis, and the company does not appear to have paved the way with much relevant research.

The company also refers to a clinical trial comparing the product to a placebo in dogs. The value of this evidence is, however, quite low as it is a study performed by the company and not apparently published in the scientific literature. Even the limited report available on the company web site suggests some problems with the study. Fifty dogs entered the trial but only 35 completed it, which is a pretty high dropout rate which could easily bias the results. Outcome measures were entirely subjective, and the reported response ranged from 10-14 points over placebo on a 100 point scale, which is of questionable clinical significance.

The company does, of course, offer plenty of testimonials to suggest the product works well, but it is well established that such testimonials are highly biased and misleading.

Is It Safe?
Once again, the answer has to be “Who knows?” The company reports no adverse effects in their unpublished clinical study, but without formal assessment under more reliable conditions, the risks are, like the possible benefits, unknown.

Bottom Line
Ultimately, real proof that a medicine is safe and effective requires careful, rigorous, and often expensive and time-consuming research. It is easier and cheaper for companies to produce supplements that can be marketed without this level of proof and then provide far less reliable sources of evidence that their products do more good than harm. Duralactin may well have benefits for patients with arthritis, though there is currently little to support this claim. And while there is no obvious reason to think it is harmful, without real research this is as much of a guess as the question of whether or not it helps.


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53 Responses to Duralactin for Arthritis

  1. Robert Boulton says:

    I have another alternative herbal remedy for arthritis being recommended by my vet that you might want to add to your list. I was a little sceptical when she recommended it but when I received the packet it read like woo too. The Australia Pesticides and Veterinary Medicines Authority approved it for use and says that it meets their guidelines for herbal medicine efficacy but I couldn’t find too much more detail than that.

  2. rita says:

    And, of course, the 64,000 dollar question – Is it Ethical? I can see no possible way victimising captive cattle – who already have miserable truncated lives because of their usefulness (or not, see recent research) to humans, even to assist medical conditions in other species, human or non-human.

    There may have been no adverse effect on the dogs in the study, but there are plenty of adverse effects on cows being milked, bereft of their young and prematurely slaughtered even without whatever murky process used here: how is this noxious process to be justified?

  3. Tyler says:

    SkeptVet, love the science-based view for the common man. But your blog is missing two things, well three, but the two big ones:

    – A custom banner at the top of your blog, other than the default WordPress theme’s picture.
    – A profile/page photo on Facebook. Right now you’ve just got an empty icon. Use a dog, or a stock photo of a vet, or a baboon – something!

    Also, do you have any DACVB friends? Would love some input on the behavior side of things with lots of cited studies.

  4. skeptvet says:

    Looks to be a Chinese herb for which there is the usual smattering of in vitro studies showing chemicals from the plant do something to cells in culture. The only research into using it for arthritis I see on PubMed is a study injecting the herb, and a bunch of other things, into the joints of horses and looking at biochemical reactions. That’s a long way from demonstrating a safe and effective product for clinical use.

    The company does reference a couple of clinical studies in dogs and horses , but as often is the case these were conducted in house and presented as abstracts at meetings rather than published in peer-reviewed sources. They seem encouraging, so it is possible there may be something to this product, but as always the jury has to remain out until the appropriate research is done, published, critically evaluated and, ideally, replicated. So “maybe but who knows?” is where I would stand on this one for now.

  5. skeptvet says:

    Yes, well as you can see from my posts, I’m more of a content than a presentation guy, and this is, after all, a labor of love fit in between my “real jobs.” I agree something more personal should go on the Facebook page, but I actually like the banner in the wordpress theme.

    As for behavior, I have had a couple of guest posts touching on the subject, but nothing regular. It’s a tough area to get solid data.

  6. Tyler says:

    Great content can be lost behind a presentation, but definitely keep the content coming.

    What if I whipped up something for those two items? I’m not an expert, but I did stay at a Holiday Inn Express last night.

    What are your thoughts on the ACVB and orgs like it (AVSAB, etc)? I’m curious to hear a non-behavior-focused vet’s views on them.

  7. Art Malernee Dvm says:

    While behavior is one of the youngest and smallest veterinary specialty groups, the field of veterinary behavior is incredibly important to our profession. Behavior problems kill more companion animals than any disease process. I can remember a local veterinarian CE meeting in the 70s where a non veterinarian popular trainer invited to lecture told the vet group to let the aggressive dog attack and then hang them with the choke collar until the dog almost passed out. This was his most successful aggressive dog training method. You still see animal trainers on tv using poor training methods. The boarded behavior vets now lecturing at the CE meetings seem to now have a large enough base of scientific knowledge to make companion animal behavior a valuable veterinary speciality in my opinion.

  8. skeptvet says:

    Well, I did a master’s degree in animal behavior prior to veterinary school, so obviously it is an area of interest for me. I think there is a mix within the field, as in vet med generally, between people dedicated to a rigorously scientific approach and those more willing to work primarily based on personal theories and experiences. It is very difficult to control for bias in a field where the outcomes are often inherently subjective to the patient and not directly accessible, but I think the best quality work is likely being done by people involved in the ACVB and other such groups.

  9. Joyce says:

    I have a neighbor whose dog is lame. I suspect hip dysplasia/arthritis but I certainly lack the knowledge to diagnose it. I’ve just had a few dogs with it and he acts similarly. What is the name of that medication that vets gave out like candy 10-12 years ago or more? For every illness/condition that caused any pain. It received a lot of bad press; whether it was justified or not, I have no idea, but I’m going insane trying to think of its name in order to look it up!

  10. skeptvet says:

    Perhaps it would be worthwhile for your neighbor to take his dog to a vet to evaluate the cause of his lameness and help choose a treatment?

  11. Jo says:

    Thank you for this article, SkeptVet! If I recall correctly, I was the one who asked you about Duralactin! I really appreciate your time and effort in researching the facts about this product.

    I’ve tried almost every arthritis-related supplement touted by many in the veterinary community as possibly effective, along with several months of Adequan injections. I’ve since come to the very frustrating and depressing conclusion that the ONLY thing that can/will help my 20 yr old cat with his osteoarthritis pain is an NSAID. Of course, I am terrified to give it considering his stage 3 CKD. The risk–including, IMO, a relatively high probability of kidney failure and thus death–vs benefit is an *excruciating* decision!

  12. skeptvet says:

    I’m sorry you’re in that tough position. There is some evidence that some cats with CKD may tolerate NSAID Tx (meloxicam has been studied a bit), but it definitely is a significant risk.

    Good luck!

  13. kathy says:

    I’ve been reading these comments on Duralactin and it not being regulated as a documented approved supplement for Dogs. I for one am a firm believer in Homeopathy alternative’s, not for just my 2 Shih Tzu’s but for me as well.
    My 11 year old Sebastian has some hip issues along with a problem with a nerve issue under the armpit. My Vet gave me Duralactin along with another med, which I deleted it from him as it was more harmful to his stomach and it made him sick.. My experience with using the Duralactin has been Over the top in helping his condition. I also give him Dasuquin with MSM.. Another option I tried was I took him to a Chiropractor and that was a MAJOR improvement. I don’t believe in harsh pain meds as they can cause a lot of bad issues.. Sebastian doesn’t act like the same Dog, he’s happy and runs and plays with his playmate Baxter.. This is just my personal take on the Duralactin which to me is much better than a Vet talking about amputation of his leg.. Research is everything..

  14. skeptvet says:

    I agree that research is important, but collecting opinions and anecdotes isn’t research, it’s gossip really. Obviously, you believe in lots of things for which the evidence is weak (duralactin) or shows that they simply don’t work (homeopathy), so you don’t appreciate how easily our experiences mislead us or why scientific research is important. You are free to believe and do what you like, of course, but the history of medicine is a compelling story illustrating why this way of deciding what works and what doesn’t isn’t truly successful.

    A few things to think about:

    Don’t Believe your Eyes (or Your Brain)

    Medical Miracles: Should We Believe?

    Testimonials Lie

    Alternative medicine and placebo effects in pets

    Placebo effects in epileptic dogs

    Medical Practices Once Widely Accepted that Proved Ineffective or Harmful when Studied Scientifically

  15. kathy says:

    Yes, I have my own opinion regarding homeopathy… but the high cost of the researched medicines, in a lot of cases causes severe health and even death. I know about 9 years ago I was given the drug Bacol for high cholestrol.. It was a new drug on the market. I took it for 3 months, lost 4 dress sizes and was wasting away.. the Doc took me off immediately and ran lots of test. Thank God I was taken off in time as it killed 52 people. It was taken off the market about 1 month after I was taken off.. I know there are lots of good researched drugs that turn out to be great. But then again, I too, get a kick out of the commercials that are advertising on TV for a specific new drug, then it tells all the side effects that would scare you to death..So for now, I will continue to do what I feel is best for me and my Shih Tzus and stay on the Natural Benefits of Health.. Thank you for your reply as we do have our own choices..

  16. To Joyce, I wonder if you are thinking about Rimadyl, the pain med which did get a terrible reputation, but from what I can read (and my own experience) it is excellent. I have to add that I once stopped going to a vet partially because of her lack of common sense about this med. I had a 9 year old Collie who could no longer get up from arthritis pain. He had been given Rimadyl once after a surgery and so I asked our vet about it for his arthritis. She said absolutely not, that it would destroy his liver and/or kidneys in 5 years. She said I should try massage, accupressure, and warm baths. I said “I have a 9 year old Collie whose life expectancy is only 10 – 12 years. In 5 years he will be gone anyway. But if we can’t relieve his pain immediately he will have to be gone now. He is in awful, glaze-eyed pain. And in any case, since he is 80 lbs. I can’t lift him to go out.” So she reluctantly gave me Rimadyl for him, with requirements for regular blood testing. In about an hour his eyes cleared, he got up, and he was on Rimadyl for his (I think) two remaining years. And I went to another vet who had a smidgin of common sense.

  17. Lisa Smith says:

    I have a sanctuary for geriatric, special needs and hospice pugs, currently have 14 residents, we tried glucosamine, didn’t work. We tried turmeric/curcumin, no results…..but it did stain EVERYTHING yellow. Someone sent me a case of Duralactin to try, and I did, no response, but it did cause stomach upset in 2 dogs enough to discontinue it. I tried colostrum, no results. Acupuncture did nothing.

    The only things that HAVE seemed to help:

    NSAIDs – I like meloxicam and piroxicam best for the oldies and protect their stomachs with cimetidine or other antacids.

    Steroids – Well, of course, but they have a whole host of problems from long term use.

    Fish Oil – I give a human capsule every day. Along with 100 mg. Vitamin E.

    Class 4 cold laser therapy – Works spectacularly for some and not at all for others.

    Hydro-therapy – If you can get your hands on an underwater treadmill ($$$$$$) they really help, swimming in a warm pool does too somewhat. I’m currently looking for plans to build my own underwater treadmill.

    Take care,

  18. Helen says:

    Dear Lisa Smith,

    If you read this, and if you’ve succeeded in building an underwater treadmill, please post here the instructions!



  19. Helen says:

    I would add, too, that my old doggie really enjoys heat applied to his arthritic areas followed by super-gentle massage. And, similarly, warm baths followed by gentle blow-dry.

  20. Helen says:

    One more comment: Anabolic steroids (e.g., testosterone) can be helpful if the arthritic condition is exacerbated by decreased muscle mass. I recognize that not all are. Anabolic steroids also improve appetite which can be a huge issue in medicating the picky eater.

  21. skeptvet says:

    Any studies you can share on this?

  22. Helen says:

    Hey thanks for asking. If you mean research on the tissue-building properties of anabolic steroids, I’m not sure any recent controlled studies would deal with that because it’s well known to be true. In people at least. Maybe it could be different in dogs? If you mean the connection between muscle strength and joint health, that’s also known. Or at least I think it is, being one of the reasons that physical therapy is recommended.

    I don’t mean to be flippant. Here are my sources:

    The Merck vet manual mentions stanozolol for muscle wasting and low appetite. So does wikipedia: https://en.wikipedia.org/wiki/Stanozolol

    I realize these aren’t research studies. They do indicate that, at least in the olden days, the drug was part of standard vet practice for these conditions. It is possible to find older members of the Theragenology Society who will describe it as “safe and effective”. I can point you to two in California. I also know people whose elderly human relatives suffering from cachexia and muscle wasting have benefited from testosterone supplementation.

    There is a vet in FL who claims it works very well for hip dysplasia in large breeds. If HD is related at all to tissue wasting then it’s not hard to believe his claim.

    Also possibly of interest is this study finding stanozolol effective in treating tracheal collapse. Anabolic (tissue building) properties at work?

    My own elderly dog recovered from debilitating TC after going on testosterone cypionate. Not body-builder levels but just enough to bring him up to a circulating level appropriate for his body size and age. His stage 2-2.5 heart murmur also disappeared.

    On my other (home) computer I have saved some research studies on testosterone side effects in humans, principally myocardial infarction (very rare in dogs) and prostate enlargement/cancer (also fairly rare even in intact dogs). There are also studies showing benefits of testosterone for people with heart failure. Will send you those links later.

    Testosterone is a controlled substance and body builders were probably getting Winstrol (stanozolol) from vets back in the 1990s, so clearly a touchy subject. Anabolic steroids are also perceived as contributing to aggressive behavior but here are some studies purporting to counter that claim wrt neutered vs. unneutered dogs. Not sure it’s included here but on my home computer I also have a user-survey study done recently that showed neutered dogs have more anxious aggression than intact.

    Michelle Bamberger, MS, DVM, and Katherine A. Houpt, VMD, PhD, DACVB Signalment factors, comorbidity, and trends in behavior diagnoses in dogs: 1,644 cases (1991–2001)
    Journal of the American Veterinary Medical Association, Vol 229, No. 10, November 15, 2006
    Behavioral assessment of child-directed canine aggression Ilana R Reisner, Frances S Shofer, Michael L Nance Injury Prevention 2007; 13:348–351

    Deborah L. Duffy, Ph.D., and James A. Serpell, Ph.D., Center for the Interaction of Animals and Society, School of Veterinary Medicine, University of Pennsylvania Non-reproductive Effects of Spaying and Neutering on Behavior in Dogs Proceedings of the Third International Symposium on Non-Surgical Contraceptive Methods for Pet Population Control, 2006

    Anthony L. Podberscek, James A. Serpell
    Animal Welfare and Human-Animal Interactions Group, Department of Clinical Veterinary Medicine, University of Cambridge, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania.
    Applied Animal Behaviour Science 47 (1996) 75-89

    The English Cocker Spaniel: preliminary findings on aggressive behaviour
    V. O’Farrell and E. Peachey
    Behavioural effects of ovario-hysterectomy on bitches Small Animal Clinic, Royal (Dick) School of Veterinary Studies, Summerhall, Edinburgh EH9 1QH
    Journal of Small Animal Practice (1990) 31, 595-598

    Hyeon H. Kim a, Seong C. Yeon a,, Katherine A. Houpt b, Hee C. Lee
    Hong H. Chang a, Hyo J. Lee
    Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
    Animal Behaviour Clinic, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA
    Effects of ovariohysterectomy on reactivity in German Shepherd dogs
    The Veterinary Journal 172 (2006) 154–159.

    I recognize that all of this sounds pretty anecdotal and honestly I think that pet owners and vets have different criteria for accepting novel treatments. The vet’s best friend is bayesian theory where you follow closely the base rates (also called priors) when diagnosing, and you treat conservatively. Averaging over all the dogs you will treat in your entire professional career, that approach gives the best outcome.

    However, a pet owner isn’t interested in statistics. S/he wants to optimize for a particular dog and often understands that particular dog with much more intuitive detail, often difficult to describe in words, than the treating vet can ever have.

    I’m close to 100% convinced that testosterone fixed my dog’s tracheal collapse, may have reduced his heart murmur, and most certainly has given him added energy, muscle mass, appetite and vigor. Based on observing him on it versus off it.

    All this said, I were playing “vet for a day” would I prescribe it freely to clients? Probably not, but would have it in my arsenal for particular cases.


  23. art malernee dvm says:

    are small animal vets starting to use a lot of winstrol again? i noticed the sports channels were making fun of a nfl football player as old school because he has been suspended for using it. 40_50 years ago small animal vets used a lot of it.

  24. Helen says:

    Art – Not in my experience. It took me a long time to find a vet willing to give my elderly dog testosterone.

  25. Helen says:

    Hello skeptvet,

    Below are some links to reports on testosterone treatment in people. I also was able to find my dog’s cardiology report from January 2, 2015. The report states:

    1. Mild mitral and tricuspid regurgitation due to degenerative valve disease – compensated 2. Probable bronchitis and tracheal collapse. Echocardiogram reveals changes to the mitral valve consistent with degenerative valve disease. Grade 3/6 L apical systolic murmur. ” This was after several vets heard mumur and gallop rhythm and the dog had been showing severe tracheal collapse symptoms for weeks.

    We started testosterone treatment in February 2015, both the murmur and the tracheal collapse disappeared, and he was happy and energetic until September 2015.

    Starting in September 2015, he began showing some concerning neurological symptoms and since then he’s been seen by several vets. None has heard a murmur during this time period. In mid-September he had a pre-MRI echocardiogram, and no evidence of mitral dysfunction was found.

    As for the references, it looks like my links are triggering your spam filter. I’m going to remove the links and just give the descriptive titles I assigned to them. Should make it easy to google. One of them is at jaha.ahajournals.org, one at http://www.endocrine.org, one at hindawi.org, several are at ncbi.nlm.nih.gov, and several are googlebooks.


    Testosterone and CHF in people
    Testosterone and Cognitive Dysfunction in people
    Testosterone and Post-Operative Frailty in people
    Testosterone Improvement of Post-Op Frailty is short-lived in people
    Testosterone in Frail Older Adults (people)
    Hormonal Changes related to Cardiac Surgery
    Testosterone and Aging (people)
    Drug Therapy for the Elderly (people)

  26. Helen says:

    On a slightly different tack, what are your thoughts on “Adequan”?

  27. Helen says:

    Dear skeptvet, my original response to your query about studies is still “awaiting moderation” while other comments I left later are not. I suspect I mistyped something. It is timestamped Dec 20 1:38 pm. If not visible to you, my apologies. Let me know if there’s some way to recover or even delete it and rewrite. Thanks!

  28. skeptvet says:

    Hi Helen,

    Thanks for the info. I agree, this is the sort of information that doesn’t really count as scientific validation for the specific claim that anabolic steroids can be beneficial in dogs with arthritis. It is a combination of anecdote, expert opinion, and extrapolation from basic principles, all of which are pretty unreliable forms of evidence. That isn’t to say the claim is wrong, simply that we can’t have much confidence in it without stronger evidence. Many such ideas, perfectly reasonable and supported by anecdote and opinion, have proven disastrously wrong in the history of medicine, so the desire for controlled evidence isn’t a pedantic or academic nicety, it is a desire for the best, safest, and most effective treatments for our pets and patients.

    Bayesian approaches, as opposed to frequentist statistical methods, are catching on, and the main reason is that p-values have been so widely misused and that clinical trial results often ignore prior probability in a way that makes their results meaningless. Still, both approaches still rely on collecting data in a way that accounts for confounding, bias, and other sources of error that make uncontrolled individual observation so unreliable.

  29. skeptvet says:

    That’s because we must always balance risks and benefits, and in the face of high uncertainty (meaning the lack of controlled research evidence), we lack the information to make a reasoned decision about this balance. This makes the use of such an intervention essentially a roll of the dice, as likely to harm as to help. In extreme cases, this may be justifiable, but most of the time, especially in a case involving arthritis, for which there are many therapies with much less uncertainty about their effects, it seems an unnecessary risk.

  30. skeptvet says:

    Of course, there are also risks in humans receiving testosterone, and this has to be considered as well: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2701485/

  31. skeptvet says:

    Not much evidence, so unclear. I have tried it from time to time, especially in cats, with no dramatic reason to think it helps.

  32. skeptvet says:

    I have no pending comments, so if it hasn’t been approved then the system ate it in some way. Sorry.

  33. Helen says:

    Dear Skeptvet,

    Thanks for this! Your points are all good but I have a couple of follow-ups as I remain unconvinced on a couple of points:

    1. Testosterone risk – That article struck me as pretty weak support for risks, especially in dogs for whom clot-related heart problems are very rare. Regarding prostate cancer, the authors seem to be severely ambivalent. In the Abstract they say “Perhaps the most controversial area is the issue of risk, especially possible stimulation of prostate cancer by testosterone, even though no evidence to support this risk exists.” Wha? A casual reader might see “prostate cancer” and “risk” in the same paragraph and conclude that prostate cancer is a concern yet there is no evidence for it? And further down the article makes your “extrapolating from principles” error when it states that prostate cancer is androgenic and so must be a likely risk.

    2. Can you point me to high quality controlled research showing that physical therapy is beneficial for osteoarthritis in dogs? This is a big deal because: a) vets recommend it frequently; b) it is expensive; c) it has clear risks (strains, inartful manipulation by strangers, drowning in the underwater treadmill as my dog almost did); d) human experiences with physical therapy are often negative.

    Testosterone treatment involves a once-a-month shot ($30-$80 depending on the vet) and walking your dog on a leash.

    3. So now a practical question. My original claim was rather limited (where “the arthritic condition is exacerbated by decreased muscle mass”) and let’s suppose that my claim is true. And let’s say further that over some period of time adventurous vets came to believe it is true by using it on clients. How would that kind of clinical “knowledge” typically become transformed into research studies that meet your criteria for validity? Do physician-conducted studies have merit, or does a university need to do it? And what would the sample size need to be? I think it would be a dead simple experimental design if you can create a placebo with the color and viscosity of the real thing.

    Thanks for this great conversation!

  34. Helen says:

    So how about this?

    I’m thinking double-blind (vet/owner). Recruit vets to participate. Each vet gets pre-set vials, some with T and some with placebo that looks and injects just like it. I.e., counterbalance within vets, not between vets. Subjects are older neutered males (to keep it simple) with the “inability-to-get-up” problem that breaks the hearts of so many owners. Since this is often the trigger for euthanasia, the risk-benefit tradeoff should be straightforward. Owner keeps a diary of the dog’s getting-up behavior. Pretest and posttest T levels. If you want to get fancy you could use different concentrations of T. However, dose-response is going to be unclear with owner diary as the only outcome variable, so I’d keep it simple and just give a standard dosage by weight. Do it every 3 weeks for 12 weeks. Next stop, publication! 🙂

  35. Helen says:

    To be clear, each dog gets T throughout or placebo throughout.

  36. skeptvet says:

    1. In terms of risks, yes, these are extrapolated from those seen in humans and may or may not apply to dogs. Direct evidence is needed to demonstrate both risks and benefits. But since you are extrapolating benefits from human evidence, I was simply showing you that the same can be done to raise concerns about safety. Without controlled research specific to the population of interest and the indication (dogs with naturally occurring arthritis and associated muscle wasting), both risks and benefits are uncertain. The tendency, unfortunately, is for people to presume that it might or might not be effective but “at least it doesn’t hurt.” The reality is that in the absence of strong evidence, harm is as likely as benefit. There are plenty of examples of this in medicine, but psychologically we tend to see what we want to see, and that means we focus on the hopeful view and ignore the potential risks.

    2. There is not yet strong evidence showing PT is beneficial in dogs. There is, however, strong evidence showing it is beneficial in people, much stronger with less concern for potentially severe side effects than for testosterone therapy. Testosterone is not generally accepted as a therapy for arthritis in humans, and in fact has been shown to be ineffective in some studies for rheumatoid arthritis (though that’s a different disease than the degenerative osteoarthritis you are presumably talking about), whereas PT is a generally accepted therapy for humans with arthritis. So while both lack direct evidence in dogs, the stronger case for safety and efficacy would be for PT.

    Now cost is a different issue. The fact that testosterone shots are cheaper than PT may influence your decision as an owner, but it’s irrelevant from the perspective of what actually works or doesn’t work and what is safe or not safe. I understand that financial reality limits our choices in veterinary medicine often, but we have to be careful not to let our discomfort with that bias us towards viewing cheaper therapies more favorably than more expensive ones without good scientific evidence to support this.

    3. This is really several different questions. Study design is complex and things like sample size calculations depend on the expected effect size and standard deviation from previous animal or human studies, and many other factors, so I can’t easily give you details of exactly how such studies would need to be organized. Placebos would likely be unethical given there exist therapies with known benefits already (e.g. NSAIDs), so a more appropriate comparator would probably be standard therapy versus standard plus testosterone and standard plus placebo, but again, the details depend on many factors.

    Generally, if someone has a hypothesis, based on theoretical reasoning, clinical experience, or something else, then someone with the appropriate expertise and resources has to be involved in designing and conducting a study. Most often in vet med, this is a commercial firm looking to sell the therapy as a product or an academic with a research interest in the subject area. With the EBVMA and other groups, I am involved in trying to encourage more research in practice, but most vets aren’t going to have the time, knowledge, or resources to do research that really answers the questions we are interested in. Having just finished a master’s in epidemiology, I can tell you good medical research is harder than it looks!

  37. Helen says:

    Dear Skeptvet,

    Item 1 – What you say certainly makes sense in general. But in particular two issues continue to rub: a) How many of the treatments in common use by vets today have passed through your strict filter of large scale fully controlled study? Are “off label” drugs tested? b) I wonder if we can equate the risk of a naturally occurring substance (whose benefits all older dogs would be enjoying, naturally, had not humans intervened to excise it from their bodies) with the risk of some new drug created in a pharma lab?

    Item 2 – Can you post links to research on the benefits of physical therapy for osteoarthritis in people? Not post-operative physical therapy. I’d love to see how they implement a placebo treatment for PT. Kind of hard to not know you’re in PT. Also just a nit: To say that PT “is a generally accepted therapy” sounds kind of like the problem we’re trying to get away from (accepting what someone told you worked for them or their patient rather than using rigorous testing).

    Item 3 – Yes it makes sense to include whatever standard treatment is already available and in place. At some point the value of NSAIDS starts to decline and owners are faced with cruel choices. “Most often in vet med, this is a commercial firm looking to sell the therapy as a product …” Ouch. 🙁

    Thanks again for your great insights.

  38. skeptvet says:

    a) How many of the treatments in common use by vets today have passed through your strict filter of large scale fully controlled study? Are “off label” drugs tested?

    Not many. Again, I’m not saying we can’t use any therapy that hasn’t been fully and appropriately tested, because that stricture would deprive us of most of our therapies, I am saying, however, that the uncertainty is high when we use therapies without this level of evidence, and we have to be cautious and circumspect about our expectations and the claims we make.

    I wonder if we can equate the risk of a naturally occurring substance (whose benefits all older dogs would be enjoying, naturally, had not humans intervened to excise it from their bodies) with the risk of some new drug created in a pharma lab?

    “Natural” is a largely meaningless term which is used to imply safety or benefit when it really doesn’t. Uranium, botulism, and rattlesnake venom are all arguably “natural,” while vaccines, antibiotics, and plenty of other life-saving medical therapies could be viewed as “artificial.” Is homeopathy “natural?” The isolation of substances which are then diluted and shaken extensively and prescribed according to a complex and thoroughly artificial theoretical system? How about herbs, which are harvested, dried, mixed together, and again administered in particular ways according to elaborate theories about health and disease? How is this like eating a plant in “the wild?” For that matter, if humans and other animals live longer and appear to be healthier for most of their lifespan in captive/”civilized” environments than in “the wild,” why would we think that the “natural” world is healthier anyway?

    The issue is not the origin of the therapy but the degree of uncertainty we have about its risks and benefits. Most of the time, “unnatural” therapies are likely safer than so-called natural ones because therapies like pharmaceuticals and surgical procedures have to be tested scientifically prior to being cleared for use, and most supplements and other supposedly “natural” therapies do not undergo this kind of testing or regulatory control. Of course, that doesn’t mean anything is perfectly safe, since anything without side effects has no effects at all. But there is a reason health and well-being have improved dramatically since we began applying science to medicine, sanitation, agriculture, accident prevention, etc., and there is good reason to think that Nature is not especially interested in the health of the individual.

    2) Again, I have not been trying to argue for PT as an arthritis treatment so much as to illustrate that the same line of reasoning used to suggest testosterone might be useful can be used to suggest PT is, and even to make a stronger case for it than for testosterone. The fact that it is widely used in humans is not, of course, conclusive evidence that it is effective. However, since many of our therapies in vet med are extrapolations from things done in humans, this sort of argument by extension is unavoidable as a low-level form of evidence. Ideally, it is followed by appropriate clinical trials in our patients, but the process is slow and imperfect and we must, of course, do the best we can in the meantime. So I am not claiming that this is strong evidence, only that it is a low-level form of evidence which, when applied in the absence of stronger evidence, still makes a better case for PT than for testosterone.

    Here are some examples of research looking at various PT interventions for arthritis in humans. I am optimistic this form of therapy will be of great value in vet med, but again I can only hypothesize that in the absence of similar research in our pets.


    “Most often in vet med, this is a commercial firm looking to sell the therapy as a product …” Ouch. 🙁

    Why? Sure, financial bias is an issue, but everybody in vet med, conventional and alternative vets, companies that make medicines, supplements, foods, etc., is making their living doing this. Apart from non-profits (e.g. Morris Foundation) and government grants (nearly non-existent for companion animals),
    research and treatment is almost entirely a commercial business, and I don’t see how it is ever going to be anything else. This doesn’t necessarily mean the therapies developed or the research done doesn’t benefit patients, only that we need rigorous standards of evidence and research design and conduct to minimize the impact of commercial bias. While everyone seems aware of the legitimate problems with medicine in a capitalist economy, it’s the reality for most of the world, in human and vet med, so we have to work with it.

  39. Helen says:

    Dear Skeptvet,

    1 – Thanks for the refs. I will definitely go and read them. And yes I’ll admit you got me on the “natural” thing. Absolutely there’s a lot of really bad “natural” stuff out there! Ha ha, I especially like snake venom. Good one! 🙂 But on the other hand I can tell you from direct experience that the absence of sex hormones has consequences. For example after playing guitar for 40+ years, by age 60 I was unable to do it any more due to osteoarthritis in my wrist. PT didn’t help, but estrogen cream applied directly to the joint did. This is not placebo effect because I wanted PT to work. Also it seems kind of cruel that young veterinarians whose own bodies are virtually flooded with sex hormones find it so easy to deny the same to older animals. There is research showing that neutering has negative effects on joint health in older animals.

    2 – “Ouch”. I’m a strong believer in private enterprise as the best mechanism for finding new solutions to old (and new) problems. But no system is perfect and sadly some good therapies may be overlooked if the potential profit is not sufficient to motivate research. I understand there are crazies out there and a lot of terrible “nutriceuticals”. Again the profit motive but without the modulating influences of government regulation. And yes, people who are otherwise intelligent fall for homeopathy and psychic readings. As you say, the need to believe is powerful. In your position you probably have to fight this battle several times per week (if not per day). It can imagine wanting to tear out one’s hair.

    Thanks, really, for fighting this battle with such intelligence and grace.


  40. Helen says:

    Dear Skeptvet,

    The PT studies are convincing. Not sure I understand the mechanism, but the agreement of multiple studies and meta analyses is compelling. IF I wanted to quibble I might say: a) The studies seem to be mostly on knees, not on necks or wrists; b) if testosterone gives you the energy and mood elevation needed to go out and exercise, then it would be contributing to a successful PT regime. This is especially relevant with dogs, who cannot have it explained to them the value of exercising “through the pain”.

    (To foil the spam filter I’ve removed all instances of http and www)

    Here’s an old one, but pretty much what I had in mind.

    Here are more recent ones.




    Koelling S, Miosge N. Sex differences of chondrogenic progenitor cells in late stages of osteoarthritis. Arthritis & Rheumatism.  2010;62:1077–1087.  Available at:  onlinelibrary.wiley.com/doi/10.1002/art.27311/abstract. 









    In summary, it looks to me as though momentum is developing, and I am ready to make a prediction. 🙂 In 10 years, treating neutered dogs with testosterone for joint, muscle-wasting, and possibly appetite, problems in old age will be standard practice.


  41. Helen says:

    Here’s a strange one. Thoughts?


  42. Helen says:

    And as long as I am pestering you … Do you have thoughts on topical NSAIDS like aspercreme (Trolamine Salicylate) and Voltaren (diclofenac sodium) for dogs? Their advantages would be ease of administration and potentially local rather than systemic effects.


  43. skeptvet says:

    Here is some discussion of this practice. And here’s a systematic review from 2009 looking at the literature on this along with other arthritis treatments.

  44. skeptvet says:

    Not generally used in small animals, so I don’t have any direct experience. Voltaren is used in horses, and there are a few studies on it. Concerns in dogs would be the lack of studies on absorption and efficacy (human and dog skin are quite different), probable need to clip hair for effective applications, likelihood of patients licking the medication and effectively getting it orally. A lot of topical drugs do actually reach measurable levels systemically, so we would have to have studies on specific drugs and formulations to be sure this wasn’t an issue. And, of course, this would only be useful for dogs who don’t tolerate oral NSAIDs, which most do. Could be helpful in some situations, but again several issues to be resolved.

  45. Helen says:

    They’re testing “elk velvet antler” — and if I have my antler knowledge right, that should be “elk antler velvet” — but no one thought of testosterone? 🙂

  46. Helen says:

    Ah I get it, it is the antler during the velvet stage.

  47. Helen says:

    Ha ha, face palm. Consider the purpose of deer antlers: fighting and getting a mate. So … who would be surprised to learn that their purported benefits are virtually identical to those of sex hormones?


    “In herbal combinations, deer velvet is used to improve athletic performance; to improve eyesight and hearing; to reduce stress; and to treat arthritis, osteoporosis, “tired blood” (anemia), women’s reproductive disorders including premenstrual syndrome (PMS), ED, and skin conditions. Herbal combinations including deer velvet are also used to increase blood circulation to the brain and to delay or reduce signs of aging such as tissue, bone, and muscle degeneration, and declining mental skills.”

  48. skeptvet says:

    Yes, the principle is called “sympathetic magic,” where a superficial resemblance or connection is believed to imply a broader or deeper relationship. Rhino horn as an aphrodisiac, walnuts as “brain food,” and so on, are examples, and velvet to support the kind of strength and vitality associated with fighting male deer. An appealing idea, but not a legitimate way to decide which natural products have which effects.

  49. Helen says:

    What’s interesting is that while what you say is exactly true and very interesting, and was my original thought, upon further consideration I realized there’s another layer here.

    Some of the properties attributed to the antler (not the velvet, the antler itself growing under the velvet) do not have strong semantic associations with masculinity but they are associated with testosterone. Here are two: 1) polycythemia is considered a testosterone risk in humans because it is associated with the formation of clots. It showed up in my dog’s blood work after a couple of months of testosterone. The article above lists anemia as a condition treated by elk antler. 2) osteoporosis is scientifically associated with low testosterone but lacks a semantic association with masculinity. The article above mentions joints and tissues.

    Based on the review article you sent, it looks like there is mild evidence for elk velvet antler being effective in osteoarthritis. I haven’t done the research but I’ll betcha the Journal of Elk Physiology would tell us that testosterone is surging in males during the period of antler growth. Would it be surprising if testosterone levels were high in the growing antler tissue itself? The wikipedia article has a paragraph about the International Anti-Doping group issuing a warning that athletes using elk antler could test positive for banned substances. What was unclear in that article is whether the antler itself was to blame or if additives were suspected. Hm ….

  50. Helen says:

    On rereading, it looks like it might be HGH, not testosterone, that was the banned substance.

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