Understanding Pro‑Stride & Joint Health in Horses
Maintaining comfortable, healthy joints is one of the biggest factors in keeping a horse sound, rideable, and mentally content. As horses age, work hard, or deal with conformational and environmental stresses, low-grade inflammation in their joints can progress to osteoarthritis and chronic pain.
Pro-Stride APS is one of the regenerative tools available in equine practice to help manage joint disease, particularly in sport and performance horses. The goal of this article is to explain what it is, how it works, and where it fits into a broader joint-health plan.
What Is Pro-Stride APS?
Pro-Stride APS (Autologous Protein Solution) is a form of regenerative medicine that uses the horse’s own blood to create a highly concentrated injection of anti-inflammatory proteins and growth factors, which is then delivered directly into the joint. It is classified as a biologic or hemoderivative therapy and essentially combines features of platelet-rich plasma and autologous conditioned serum. The processing system separates and concentrates these components stall-side in a two-step device to produce an APS injection that is typically used intra-articularly. (Zoetis)
How Does Pro-Stride Support Joint Health?
Inside an inflamed or arthritic joint, pro-inflammatory cytokines drive pain and cartilage breakdown. Over time, this cycle leads to cartilage thinning, osteophyte formation, joint effusion, and lameness.
Pro-Stride APS is designed to increase anti-inflammatory proteins that help block damaging cytokines such as interleukin-1 and TNF-alpha, while also delivering growth factors that can support cartilage, synovium, and surrounding soft tissues. By modulating the joint environment, it aims to make the joint less catabolic and more balanced. Clinical work and early research suggest APS injections can reduce lameness and joint pain, improve comfort and performance, and may provide relief lasting several months in appropriate cases. It also offers a steroid-free option, which can be attractive for competition horses or horses where repeated corticosteroid exposure is a concern. (Atlantic Equine Services)
When Might A Veterinarian Recommend Pro-Stride?
In day-to-day practice, Pro-Stride is most commonly considered for horses with:
• Osteoarthritis or degenerative joint disease
• Chronic joint inflammation or synovitis
• Select soft-tissue–related joint problems, depending on the specific diagnosis
It is often discussed when traditional joint injections with corticosteroid and hyaluronic acid are helping but need to be repeated more frequently than ideal, when the owner prefers a more biologic, autologous option, or when we are trying to reduce overall steroid exposure or extend the interval between steroid injections.
Pro-Stride is not a cure-all. It is likely to work best when there is a clear diagnosis based on a lameness exam, diagnostic analgesia, and imaging, when there is still reasonable joint structure to preserve, and when it is combined with appropriate farriery, conditioning, footing management, and body-weight control. (Mad Barn Canada)
What Does The Procedure Involve?
While exact protocols vary between veterinarians and practices, a typical Pro-Stride appointment includes:
Lameness assessment or recheck to confirm which joint or soft-tissue structure is the primary pain source and to confirm that APS is a sensible option.
Blood collection from the horse into specialized Pro-Stride or APS tubes.
On-site processing using a portable centrifuge and dedicated device. The blood is spun and passed through specific media to concentrate platelets, white cells, anti-inflammatory cytokines, and growth factors into a small volume of APS. This process generally takes under 30 minutes and can be done stall-side.
Joint injection, usually with the horse sedated. The area is clipped and aseptically prepared, and the APS is injected into the joint or, in some cases, into a soft-tissue structure.
Aftercare, which often includes a short period of rest or light work and a gradual return to the horse’s job. Mild post-injection soreness can occur for a day or two. Improvement is typically assessed over the following days to weeks, with the intent of maintaining better comfort over months. (EquidDoc Veterinary Services)
Risks, Limitations, And Evidence
As with any intra-articular therapy, Pro-Stride carries some risk. These include transient joint flare or increased lameness, and the rare but serious risk of joint infection. In horses with very advanced, end-stage arthritis, APS alone may not provide the desired improvement.
The evidence base for APS in horses is growing but still smaller than that for traditional therapies such as corticosteroids and polysulfated glycosaminoglycans. Experimental and clinical studies in horses and other species show that APS can decrease markers of inflammation, improve lameness scores, and may improve synovial and cartilage parameters in certain models of joint disease. Overall, it should be viewed as one tool within a larger osteoarthritis management strategy rather than a stand-alone solution. (Frontiers)
Pro-Stride As Part Of A Joint-Health Plan
Even a very effective injection cannot fully compensate for poor management or an inappropriate workload. APS is best used as part of a comprehensive plan that may include:
• Balanced farriery and attention to hoof conformation and support
• Thoughtful training and conditioning with adequate warm-up, cool-down, and rest
• Footing management in arenas, turnout areas, and competition venues
• Weight management and overall metabolic health
• Appropriate use of systemic therapies such as NSAIDs, polysulfated glycosaminoglycans, or intravenous hyaluronic acid where indicated
• Adjunctive modalities like physical therapy, acupuncture, chiropractic care, or shockwave in selected cases
Is Pro-Stride Right For Your Horse?
Deciding whether to include Pro-Stride in a treatment plan is case specific. As an equine veterinarian, I would consider the underlying diagnosis, the stage of disease, the horse’s job and competition schedule, previous response to joint therapies, the owner’s goals and expectations, and the overall management picture.
For some horses, APS may help extend a comfortable working lifespan, reduce reliance on intra-articular steroids, or offer an option when other treatments are no longer providing adequate benefit. For others, particularly those with severe joint remodeling or multiple concurrent issues, it may be one of several supportive steps rather than a game-changer on its own.
A thorough lameness evaluation and a detailed discussion with your veterinarian remain the best way to determine whether Pro-Stride is an appropriate part of your horse’s long-term joint-health strategy.
Further Reading And Selected References
• Zoetis: Pro-Stride APS product information and overview of indications, mechanism, and handling. (Zoetis)
• Mad Barn: Autologous Protein Solution (Pro-Stride) therapy article reviewing preparation, science, and clinical use in horses. (Mad Barn Canada)
• Linardi RL et al., Frontiers in Veterinary Science (2019): In vitro evaluation of APS effects on inflamed chondrocytes and cytokine concentrations. (Frontiers)
• Bertone AL et al., American Journal of Veterinary Research (2014): Evaluation of a single intra-articular APS injection for equine osteoarthritis. (AVMA Journals)
• Usimaki A et al., Equine Veterinary Journal (2025): Effects of a single intra-articular APS injection in an interleukin-1 beta–induced synovitis model in horses. (PubMed)
• Abd Razak HRB et al., Clinical review on APS as a promising therapy for osteoarthritis, including equine data. (PMC)
• EquidDoc Equine Clinic: Client-facing overview of Pro-Stride APS use in practice, including practical benefits and procedure description. (EquidDoc Veterinary Services)