Long-Term Survival Following Synovial Lavage in Horses 

Contaminated or septic synovial structures in horses are challenging for practitioners to resolve. In a 15-month prospective study across 10 referral hospitals in the United Kingdom, researchers investigated horses’ long-term survival after synovial lavage of contaminated and septic synovial structures.  

Study Population

The study included 240 horses with at least two of the following criteria:  

• Lameness localized to a synovial structure.  

• Joint effusion.  

• Heat or pain on palpation.  

• Increased nucleated cell counts with at least 75% neutrophils.  

• A positive bacterial culture.  

The fetlock, digital flexor tendon sheath, and tarsocrural joint were the most common synovial structures involved. 

Survival Following Synovial Lavage

Researchers used various techniques to perform lavages, including endoscopy, arthrotomy, and through-and-through needle lavage. One-quarter of the horses had concurrent osseous, cartilage, or soft tissue pathology and/or foreign material involved with their septic synovial structure. Of the 240 horses treated with lavage, 201 survived to discharge, and eight were euthanized. A second lavage was necessary for 31 horses, with 24 of them surviving to discharge and two euthanized. A third lavage was performed on five horses, with three surviving and two euthanized. 

Overall, 95% (228/240) of horses survived to discharge, and overall long-term survival was 89% (185/207).  

Certain variables were associated with nonsurvival, including forelimb involvement, unknown cause of sepsis, heavy body weight, long duration of surgery, and type of synovial structure affected (i.e., tendon sheath or bursa vs. a joint). 

Final Thoughts

In summary, despite the seriousness of sepsis in a synovial structure, the prognosis is excellent for survival to discharge and long-term survival. The authors reported that synovial lavage—performed in 92.5% of the cases in this study—might be a key factor in survival. The researchers did not evaluate soundness in this study. 

Reference

de Souza TC, Burford J, Busschers E, Freeman S, Suthers JM. Multicenter study investigating long-term survival after synovial lavage of contaminated and septic synovial structures in horses presented to 10 UK referral hospitals. Vet Surg. 2024 Aug;53(6):1083-1092. doi: 10.1111/vsu.14107

Related Reading

• Chlorhexidine Flush: Potential Treatment for Septic Arthritis in Horses?
• What We Know About Septic Bicipital Bursitis in Horses
• Disease Du Jour: Regional Limb Perfusions

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