Medical treatment of horses with ileal impactions: 1 0 cases (1 990-1 994) R. Reid Hanson, DVM; John Schumacher, DVM, MS; Jay Humburg, DVM, MS; Suzann Carson Dunkerley, DVM Objective-To evaluate clinical and laboratory findings for horses treated medically for ileal impactions. Design-Retrospective case series. Animals-10 horses with primary ileal impaction that were treated successfully with medical treatment alone. Procedure-Medical records were reviewed for all horses with naturally developing ileal impaction seen at our hospital between 1990 and 1994. Results-Transrectal palpation revealed an impaction in the midabdominal area in all horses. Generalized disten- tion of the small intestine was evident in 6 horses, whereas 4 horses were examined early in the course of the condition and did not have intestinal distention. Treat- ment consisted of intravenous administration of a bal- anced electrolyte solution, nasogastric intubation and siphonage, and administration of analgesics. Mineral oil was administered after gastric reflux had ceased. Mean time for resolution of ileal impaction was 11.7 hours. Clinical Implications-Medical treatment may be a vi- able alternative for horses that cannot have surgery, pro- vided persistent signs of severe pain or progressive gaseous distention of the small intestine are not features of the condition. Improvement of cardiovascular status, reduction in signs of abdominal pain, decrease in disten- tion of loops of small intestine during repeated transrectal examination, softening of the impaction, and decreases in amounts of gastric reflux were indicative of a response to medical treatment. (J Am Vet Med Assoc 1996;208: 898-900) I leal impaction is the most frequently reported cause of nonstrangulating obstruction of the small intes- tine in adult horses.'.2 Surgical intervention has been the most popular method of treatment for correction of ileal impactions, because early recognition of the necessity for surgical intervention has been paramount to the successful treatment of horses with this condi- ti~n.~,~ Surgery generally is indicated when serial trans- rectal palpations of the abdomen reveal persistent distention of the small intestine, rather than an im- paction of the ileum that becomes progressively smaller with time.5,6Deterioration of the horse's cir- culatory function, combined with progressive intesti- nal distention, provide the primary reasons for the decrease in survival rates associated with increasing time from onset of the condition to surgical interven- ti~n.~ From the Department of Large Animal Surgery and Medicine, College of Veterinary Medicine, 133 McAdory Hall, Auburn Univer- sity, AL 36849-5522. Published as College of Veterinary Medicine, Auburn University publication series No. 2489. The authors thank Mrs. Debi Burelle for technical assistance. Veterinarians have been reluctant to treat horses with an ileal impaction by use of medical management alone. Horses with ileal impaction are often subjected to celiotomy for correction of ileal impaction even though cardiovascular status is good and signs of pain are controlled by the use of analgesics and nasogastric siphonage. To our knowledge, clinical reports have not detailed the use of medical management for the treat- ment of ileal impaction in horses. As a result, clinical signs, indications for nonsurgical intervention, and mortality rates associated with medical treatment are not well described. Therefore, the purpose of the study reported here was to describe the clinical course and medical management of horses with ileal impaction that caused acute onset of signs of abdominal pain. Criteria for Selection of Cases Medical records were reviewed for 48 horses that had ileal impaction between May 1990 and October 1994. Horses were included in the study when an ileal impaction was palpable per rectum and financial con- straints imposed by the owners precluded the use of surgical intervention for correction of the condition. The following information was extracted from each record: breed, age, sex, duration of clinical signs before admission, rectal temperature, heart rate, respiratory rate, PCV, total protein concentration, quantity of ma- terial that refluxed through the nasogastric tube, re- sults of the per rectal examination for the detection of gas or fluid distention of the small intestine, and in- terval from initiation of treatment until resolution of the impaction. Results Signalment-Horses ranged from 2 to 13 years old. Five horses were females and 5 were geldings. Breeds represented included Quarter Horse (5), Amer- ican Saddlebred (2), Appaloosa (l), and Tennessee Walking Horse (l), and there was 1 mule. Number of hours for which signs of continuous, moderate abdom- inal pain were noticeable before hospitalization was 3 to 48 hours (mean + SD, 11.6 + 14.3 hours). At the time of examination at our hospital, 7 of 10 horses had a slight increase in heart rate (50 to 60 beatslmin). All horses had a reduction in the frequency and volume of borborygmi, but respiratory rate, rectal temperature, mucous membrane color, and capillary refill time were considered normal. In all horses, an 8 to 10 cm in diameter, doughy impaction of the ileum was palpable just medial to the cecum. This impaction extended for 40 to 80 cm aborally from the base of the cecum. Signs of abdominal pain could be elicited when the impacted intestine was retracted ventrally. Reflux through a na- sogastric tube and distended small intestine that was 898 Retrospective Study JAVMA, Vol 208, No. 6, March 15, 1996