Abnormal conditions of the equine descending (small) colon: 102 cases (1979-1989)

Abstract

Summary The signalment, clinical and laboratory findings of surgical conditions, treatment, and outcome of 102 cases of descending colon disease in horses were reviewed. Abnormal conditions were categorized as enteroliths, impactions, strangulating lipomas, fecaliths, foreign body obstruction, volvulus, nephrosplenic entrapment, and other conditions. Eleven breed categories of horses were seen during this period. Arabians, ponies, and American miniature horses were more predisposed to descending colon disease than other breeds (P < 0.05). Female horses and animals >15 years old were more likely to be affected with descending colon disease, whereas horses <5 years old were less likely to be affected (P < 0.05). More specifically, Arabians, Quarter Horses, and Thoroughbreds >10 years old were breeds that were overrepresented when compared with the hospital population (P < 0.05). Enteroliths were most commonly seen in horses between 5 and 10 years old (P < 0.05) and were not seen in horses <2 years old. Enteroliths had a tendency to develop more commonly in Arabians and in female horses. Impactions affected horses >15 years old (P < 0.05) and had a greater tendency to affect ponies and American miniature horses. Female horses were more commonly affected by impaction than were males. Strangulating lipomas were commonly seen in horses >15 years old (P < 0.05) and more specifically female Quarter Horses (P < 0.05). Fecaliths tended to be a disease of horses <1 year old or >15years old and affected males more commonly than females. Ponies, American miniature horses, mixed-breed horses, and mustangs were the breeds most commonly affected. Surgical conditions were categorized as vascular (16%) or nonvascular (84%) conditions. Vascular conditions included strangulating lipomas (6%) and other conditions (10%). Nonvascular conditions included enteroliths (40%), impactions (25%), fecaliths (13%), and other conditions (6%). Horses with vascular lesions were older than horses with nonvascular conditions (P < 0.05). Peritoneal fluid values were high for all surgical conditions of the descending colon. Nucleated cell count and total protein concentration in peritoneal fluid retrieved from horses with vascular lesions were higher than in horses with nonvascular lesions (P < 0.01). Palpation per rectum revealed abnormal findings more commonly in horses with vascular compromise (P < 0.05). Of those horses taken to surgery, 91% were recovered from anesthesia and discharged; 90% of horses, for which the condition was monitored to at least 6 months after surgery, were alive. All horses that were medically treated were alive at least 6 months after discharge.