When addressing equine joint disease (arthritis), veterinarians must match treatment to the affected tissue type, the horse’s overall health, and the underlying cause of disease to reduce complications and improve outcomes. Kimberly Hallowell, DVM, Dipl. ACVIM (LAIM), a PhD student at North Carolina State University, in Raleigh, and Lauren Schnabel, DVM, PhD, Dipl. ACVS-LA, Dipl. ACVMSR, professor of equine orthopedic surgery and Hallowell’s mentor in the PhD program, presented on the topic at the 2026 American College of Veterinary Internal Medicine Forum, held June 11-13 in Seattle, Washington.

Osteoarthritis affects the structures in the horse’s joint capsule, the synovial membrane lining it, synovial fluid, subchondral bone (which lies beneath the cartilage), and surrounding soft tissues such as tendons and ligaments, contributing to pain and lameness. This means no single therapy works for every horse.

“The goal is to intervene early, treat the underlying injury, restore joint homeostasis, and return the horse to its highest possible level of athletic function,” Schnabel said. In many cases that involves combining therapies rather than relying on a single treatment.

Corticosteroids for Treating Equine Joints

Corticosteroids remain one of the most used intra-articular treatments because they provide powerful anti-inflammatory effects at a relatively low cost. “However, growing evidence suggests veterinarians should carefully consider each horse’s metabolic health before administering these medications,” said Hallowell.

Intra-articular corticosteroids can cause temporary increases in insulin and blood glucose concentrations, raising concerns about corticosteroid-associated laminitis, particularly in horses with insulin dysregulation or equine metabolic syndrome (EMS). For horses with confirmed or suspected EMS, she recommended considering orthobiologics or polyacrylamide hydrogels (PAAGs) instead of corticosteroids.

Orthobiologics and PAAGs for Treating Equine Joints

Orthobiologic joint therapies for horses include autologous conditioned serum (ACS, also known as interleukin-1 receptor antagonist protein ), platelet-rich plasma (PRP), autologous protein solution (APS), alpha-2 macroglobulin (A2M), and stem cell therapies. Because these products originate from the individual horse, however, their composition can vary considerably. “Hydration status, recent exercise, stress, and medications, in addition to blood collection and storage techniques, can all influence the final product’s quality,” said Schnabel. Following standardized collection protocols helps maximize treatment consistency.

“Injectable polyacrylamide hydrogels give veterinarians another option for managing osteoarthritis,” Schnabel added. “These synthetic products integrate into joint tissues or supplement joint lubrication depending on the formulation.” The 2.5% PAAG product acts through integration in the synovial membrane, while the 4% PAAG product provides viscosupplementation and aggregates in areas of damaged cartilage, she explained.

Equine Endocrine Disease and Joint Therapies

Hallowell said veterinarians should test horses with possible endocrine disease before selecting a joint therapy. In fact, she recommended making endocrine screening part of routine preventive care by testing horses over the age of 15 for PPID and evaluating all horses for EMS with a dynamic test such as the oral sugar test.

Although horses with signs of EMS, such as regional fat deposits, generalized obesity, intermittent foot soreness, or divergent hoof growth rings, should be highest priority for testing, Hallowell highlighted that she and her colleagues recently found almost 25% of sport horses have EMS, and even horses without classic clinical signs can be affected.

These screenings can be incorporated into annual wellness exams, and point-of-care insulin tests now make it possible to assess many horses’ metabolic status on the day of treatment. “Identifying endocrine disease before joint therapy can help veterinarians select the most appropriate treatment and better manage potential risks,” said Hallowell.

Take-Home Message

Schnabel and Hallowell emphasized that successful joint therapy depends on accurate diagnosis and individualized treatment. Matching therapy to the injured tissue and the individual horse’s health offers the best opportunity to improve soundness while minimizing treatment-related risks.