Autologous conditioned plasma (also known as platelet-rich plasma, PRP), autologous conditioned serum (ACS), autologous protein solution (APS), cellular products like stem, stromal, and progenitor cell therapy, and polyacrylamide hydrogel are relatively new injectable joint therapies for horses. Scientists still don’t fully understand their use and benefits in the horse, but the fact that increasingly more practitioners are offering them suggests people find them helpful. It also means researchers will be able to collect more information regarding their use in clinical cases, said Lindsey Boone, DVM, PhD, Dipl. ACVS, an assistant professor of equine surgery and sports medicine at Auburn University’s College of Veterinary Medicine, in Alabama.

“These products have a place in the treatment of joint injury, and the more we use them the more we will learn, for the benefit of our equine athletes and partners,” she said.

Nearly 90% of 350+ Practitioners Surveyed Use NSIATs

Boone and her fellow researchers conducted a survey of more than 350 veterinarians, primarily in the U.S. and Canada. The practitioners, most of whom specialized in equine patients, answered 59 questions about their use of therapies for joint injections.

They found that 87.5% of respondents use NSIATs—motivated by their own experience in practice and/or encouraging results in scientific studies, Boone said. The veterinarians most likely to use NSIATs were those that performed injections in more than 10 horses per month and/or who had a higher caseload of lameness compared to other pathologies.

“This was not surprising to me given that the equipment and disposables for these commercially available kits can be pricey,” she said. PRP, ACS, and APS, in particular, often include a specific—and very expensive—centrifuge. “Therefore, it only makes sense that practices with a higher equine caseload would be able to support such units and that they would have more opportunity to also use these products.”

Among NSIATs, the most common to least commonly used products were ACS and PRP, followed by APS, cellular therapies, and polyacrylamide hydrogel—although European veterinarians were more likely to use polyacrylamide hydrogel (which was marketed earlier in Europe) than North American veterinarians, Boone said.

The researchers found NSIAT use was more popular among practitioners working with English disciplines than Western, leisure, or other disciplines, said Boone. However, that might be a result of the sample population of veterinarians who responded to the survey, she said.

NSIATs Still Second To Corticosteroids

Overall, NSIATs were not necessarily the preferred first-line injectable treatment for acute and chronic articular pain, Boone said. Corticosteroids with or without hyaluronic acid remained the most popular, consistent with a 2009 survey of American Association of Equine Practitioners members.

That might be due to a lingering lack of clarity about the benefits of NSIATs in addition to their relative expense, said Boone. It’s also possible that owners are reluctant to try to them simply because they’re unfamiliar with them. “I think the use or disuse of these products by practitioners are confounded by many variables driven by goals for treatment of the patient, practitioner experience and knowledge of the product, owner experience, knowledge of the products, equipment availability, and more,” she said.

Time—and further research—could lead to changes in how NSIATs are being used, how often they’re administered, which veterinarians use them, and which horses receive them, Boone said.

“There is still so much to learn about these NSIATs regarding their use,” she said. “It is difficult to compare these products in the (scientific) literature due to the number of systems available for each product. All of these products will differ slightly in their output even when the same horse on the same day is used to process the product. And that’s not to mention that the end biologic product not only relies on the proprietary processing methodology of the system but also the physiologic status of the patient.”

Many NSIATs are autologous—meaning they are developed from biological products taken from the horse itself and reinjected. “This means the end product will differ from horse to horse and day to day, making outcomes very difficult to compare between studies,” said Boone. “Additionally, the assessment of injury and reason for treatment will vary between studies and often lack adequate controls.”

Trusting Your Vet To Make the Right Choice, Together

The study isn’t meant to suggest that owners should change veterinarians if they want to get NSIAT treatment for their animals, Boone added.

“Your veterinarian uses the information available to decide if the use of these products is warranted for your horse,” she said. “He or she has his or her reasons for recommending or not recommending their use. Trust in your veterinarian is required in a strong veterinary-client-patient relationship. If you are interested in using the product, ask your veterinarian about them and get his or her thoughts, but trust the veterinarian’s assessment and recommendations for treatment of your horse.”