Evaluation of enterolithiasis in equids: 900 cases (1973-1996).

OBJECTIVE: To identify breed, age, sex, physical findings, history, and outcome of treatment in horses and other equids with enterolithiasis. DESIGN: Retrospective study. ANIMALS: 900 equids with enterolithiasis. PROCEDURE: Medical records from equids with enterolithiasis admitted between 1973 and 1996 were reviewed. Data on signalment, history, physical examination and clinicopathologic findings, surgical findings, and outcome were compiled from records and from telephone interviews with owners. Sex and breed predilections were determined by comparison of the study population with the general hospital population of equids during the same time period. RESULTS: Equids with enterolithiasis represented 15.1% of patients admitted for treatment colic, and 27.5% of patients undergoing celiotomy for treatment of colic. Arabian and Arabian crosses, Morgans, American Saddlebreds, and donkeys were significantly overrepresented, and Thoroughbreds, Standardbreds, warmbloods, and stallions were significantly underrepresented in the study population, compared with the hospital population. The mean age of equids with enterolithiasis was 11.4 years. The most common historic findings were signs of intermittent colic (33.3%) and passage of enteroliths in the feces (13.5%). Physical examination findings were similar to those found in equids with other forms of nonstrangulating large colon obstructive disease. Fifteen percent (131) developed gastrointestinal tract rupture caused by an enterolith that necessitated euthanasia. Short-term and 1-year survival rates for equids undergoing celiotomy for treatment of enterolithiasis and recovering from anesthesia were excellent (96.2 and 92.5%, respectively), and postoperative complications were uncommon. Recurrence of enterolithiasis was identified in 7.7% of the study population. CLINICAL IMPLICATIONS: Results indicated that shortterm and 1-year survival rates for equids undergoing surgery for enterolithiasis are excellent. Identification of signalment, history, and management factors may help identify equids with a high risk for development of enterolithiasis.