Two-route drug combination best for horse joint pain

By Sarah Guy, medwireNews Reporter

A combination of systemic nonsteroidal anti-inflammatory drugs (NSAIDs) plus intrasynovial glucocorticosteroids is superior to either medication alone in improving outcomes for lame horses with perisynovial pain of the metacarpophalangeal joint (MCPJ), report Dutch researchers.

Significantly more horses returned to their previous level of performance within 6 months when treated with the combination compared with their counterparts treated with NSAIDs or glucocorticosteroids alone, show the study results.

"A possible explanation for the better outcome is that glucocorticosteroids primarily suppress the inflammatory process in the synovial membrane/submembrane fibrous layer, and NSAIDs also suppress the inflammatory reaction in the fibrous part of the joint capsule and perisynovial tissues," say Harold Brommer and colleagues from the University of Utrecht.

The ultimate measure of treatment efficacy for any equine orthopedic issue is the ability to alleviate lameness, they explain.

The team retrospectively identified 104 horses that presented between 2004 and 2007 with perisynovial pain of the MCPJ, distal interphalangeal joint (DIPJ), or the digital flexor tendon sheath (DFTS), and which were treated with NSAIDs (n=40; group 1), intrasynovial glucocorticosteroids (n=30; group 2), or a combination of both (n=34; group 3).

Significantly more horses in group 3 had a successful outcome, at 55.9%, than horses in groups 1 and 2, at 27.5% and 26.6%, respectively, report the researchers in Veterinary Record.

Multivariate analysis showed that while factors including breed, age, and duration of lameness had no association with outcome, treatment group, and the synovial structure affected significantly correlated with return to full functioning within 6 months after treatment.

Specifically, horses in treatment group 1 and 2 were a respective 79% and 82% less likely to have a successful outcome compared with horses in group 3.

Conversely, and relative to their counterparts with perisynovial pain of the DIPJ, horses with involvement of the MCPJ and DFTS were a significant 4.18 and 5.59 times more likely to have a successful outcome, respectively.

Brommer and co-authors highlight the possibility that the lameness in the horses in their study is "likely to recur" if the underlying cause is not addressed once the treatment effects wear off. They also suggest a prospective, randomized clinical trial to increase the evidence for their findings.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.