Deep digital flexor tenotomy as a treatment for chronic laminitis in horses: 35 cases (1988-1997)

OBJECTIVE: To determine long-term prognosis for horses with laminitis treated by deep digital flexor (DDF) tenotomy and to identify factors affecting success of the surgical procedure. DESIGN: Retrospective study. ANIMALS: 35 horses with laminitis treated by DDF tenotomy between 1988 and 1997. PROCEDURE: Information was obtained from individual medical records and follow-up telephone interviews with owners and referring veterinarians. Cumulative proportions of horses that survived 6 months and 2 years after tenotomy were determined. Effect of Obel grade of lameness on 6-month and 2-year survival and effect of distal phalangeal rotation on survival and future performance were evaluated by chi 2 analysis. Body weights of horses that survived > or = 2 years were compared with those of horses that survived < 2 years by ANOVA. RESULTS: 27 of the 35 (77%) horses survived > or = 6 months, and 19 of 32 (59%) survived > 2 years. Obel grade of lameness and body weight at time of surgery had no effect on 6-month or 2-year survival. Degree of distal phalangeal rotation had no effect on 2-year survival or the ability of horses to be used for light riding. Twenty-two of the 30 (73%) owners interviewed indicated they would have the procedure repeated on their horses given similar circumstances. CLINICAL IMPLICATIONS: DDF tenotomy is a viable alternative for horses with laminitis refractory to conventional medical treatment. In some instances, the procedure may be effective in returning horses to light athletic use.