Encouraging Study of Platelet Therapy for Arthritis in Dogs

Though I write frequently about potential arthritis therapies, particularly emerging treatments and those that are established but seem to have a questionable evidence base, I haven’t yet run across the therapy evaluated in a study recently published in the journal of the American veterinary Medical Association: injection of a dog’s own platelets into an arthritic joint.

Fahie MA, Ortolano GA, Guercio V, et al. A randomized controlled trial of the efficacy of autologous platelet therapy for the treatment of osteoarthritis in dogs. JAVMA 2013;243(9):1291-7.

This was a small but nicely done trial which involved dogs with documented symptomatic arthritis in a single joint. Though this is an unusual situation, since most dogs with arthritis have it in multiple joints, this population was selected to minimize confounding variables and simplify the evaluation of the test treatment.

 Subjects were appropriately randomized to placebo or the test treatment, and all treatments and evaluations were done by individuals blind to the treatment group. This helps to minimize potential bias or placebo effects. At the start of the study, two subjective measures of comfort and function (questionnaires) were completed by owners, and an objective measure (amount of weight placed on the affected leg) was also evaluated. Dogs in the test group received a single injection of their own concentrated blood platelets in the affected joint, and control group dogs received a saline injection in the affected joint. The subjective and objective measures were repeated at 12 weeks after treatment.

One encouraging feature of this study was the consistency of the outcomes. Both subjective and outcome measures were statistically improved in dogs in the treatment group and not in dogs in the control group. Subjective measures improved by 55%, and the objective measure improved by 12%.

There are, of course, a few caveats. The study was quite small, and in some of the objective tests only 5 dogs were evaluated in each group. The influence of chance on the results, and the potential applicability of the results to the general population, are always uncertain with such a small number of subjects.

And there is also always the question about the clinical significance of the effect. A 55% change in perceived symptoms seems a large enough difference to be meaningful, though as always it is being assessed indirectly through the owner, so whether the discomfort experienced by the dog is truly that much improved is impossible to know. However, a 12% difference in the measure of weight bearing is quite a bit smaller, and it is not clear how significant such an improvement would be in the comfort and function of a dog with arthritis.

Overall, this is a well-done study that provides an encouraging tidbit of evidence for this particular treatment. The authors’ conclusion is supported by the data, and they do not oversell the results. Larger studies will certainly need to be done to confirm the findings, and studies of more typical patients with multiple arthritis joints and other concurrent medical conditions will be needed before we can confidently predict the results of such a therapy in the general population. As with stem cell therapy, autologous platelet therapy seems promising, but hopefully the scientific research will lead the way forward rather than the commercialization and marketing efforts for this therapy.



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13 Responses to Encouraging Study of Platelet Therapy for Arthritis in Dogs

  1. Jana Rade says:

    Our vet started using PRP therapy about a year ago.

  2. Art says:

    Any human prospective randomized study? If one dog study says it works for dogs I would think someone is already putting platelets in basketball players knees somewhere in the world.

  3. skeptvet says:

    There are a number of papers on the subject, but no systematic reviews, and I have’t investigated the human literature in any depth.

  4. Diane says:

    What is the theory or mechanism behind injecting platelets?

  5. skeptvet says:

    There isn’t a clear, validated mechanism. Platelets contain a large number of biologically active compounds, and it is theorized that some can induce regeneration of cartilage, affect inflammation, reduce oxidative damage, and a number of other functions. There is some in vitro research to suggest platelts might have some of these effects, but whether this translates into an effective clinical therapy is not absolutely clear. In my opinion, the evidence is currently at the “promising” stage.

  6. Diane says:

    Thanks. That’s fascinating, I can’t wait to hear about more research.

  7. Art says:

    I would make one of the the placebos the patients whole blood with no anticoagulate added that was not in the platelets . Some Vets in Europe will treat Cruciate tear with injections of whole blood into the joint and make the claim it works as well as Cruciate surgery. I would like to see adequan tested with blood not sterile saline as a placebo

  8. Helen says:

    Two years have now passed since this was first written. Have any studies advanced beyond the “promising” stage?

  9. skeptvet says:

    I haven’t seen any studies since the one discussed in this post. Two years is a pretty short time in the world of new drug research, especially in veterinary medicine where the resources are so scarce.

  10. Helen says:

    That’s too bad. 🙁

  11. I just discovered your blog tonight. Thanks so much for this, Brennen! Wow — what a tremendous amount of work you put in to helping people make informed decisions in a confusing world of real and bogus (or at least, unbacked) treatments. Much appreciated!

    I do wish we had more studies on using PRP to help treat arthritis in dogs. I’m still considering trying it on my best friend (in addition to keeping her on her pain meds, Dasuquin, and Cartrophen). I’m okay with taking a risk on wasting my money on a PRP treatment that doesn’t work (and I already have a cost estimate). My concern, though, would be whether it’s safe (given the lack of studies to tell us). Vets tout that because they use the dog’s own platelets, it’s a lower-risk procedure. But I’d be curious about your thoughts on that.

  12. skeptvet says:

    Thanks for the feedback. I’m glad the blog is useful for you.

    You’re right that without appropriate studies it is hard to be certain about safety. The FDA has decided not to regulate autologous veterinary stem cell therapies (where the stem cells come from the patient’s own body) since they are perceived to be lower risk, so the same logic might apply to PRP. And the International Society for Stem Cell Research says this:

    “Cells from your own body are not automatically safe when used in treatments– The use of a patient’s own cells is called an autologous transplant. However, the processes by which the cells were acquired, grown and then reintroduced into the body would carry risks. Here are just a few known risks of autologous stem cell treatments:

    Any time cells are removed from your body, there is a risk they may be contaminated with viruses, bacteria or other pathogens that could cause disease when reintroduced
    Manipulation of cells by a clinic may interfere with their normal function, including those that control cell growth
    How and where the cells are put back into your body matters, and some clinics inject cells into places where they are not normally present and do not belong”

    Again, this refers to stem cells, but it’s a similar issue with PRP. While I would guess the risk is pretty low, unfortunately that is still just a guess.

  13. Carolyn says:

    Thanks very much for this!

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