Summary
The purposes of referring a horse to a surgical facility are: 1) to place the horse in an environment where aggressive and intensive treatment can be applied before the horse’s condition begins to deteriorate; 2) to place the horse in a facility where long term medical therapy can be applied (as for impaction colic or enteritis); and 3) to place the horse in a facility where it can be monitored continuously. If surgery is needed, its goal is to correct the primary problem before the horse develops irreversible changes in its intestine or in other organs.
Assessment of the horse with colic requires an overall impression of the horse’s physical status, without emphasis on any one abnormality, but with due regard for all clinical signs and physical examination findings. In the author’s experience, pain, cardiovascular status, and abdominal distension, alone or in combination, provide the most apparent and sensitive measures of the severity of colic. Response to analgesics, such as flunixin meglumine or xylazine, is extremely important. An unsatisfactory response, such as a heart rate that remains at or above 48 beats per minute, in spite of an initial decrease, and continued signs of pain, warrants referral and, if needed, surgery. Rectal examination findings can be helpful if positive, but not if negative.
Pain and abdominal distension are marked in horses with large colon volvulus but other colonic diseases can be less obvious and can have pain of variable intensity. Small intestinal diseases can start with severe pain and no distension in an adult and then the degree of pain decreases as the horse develops endotoxic shock. Abdominocentesis should not be used in adult horses with abdominal distension, in foals (unless absolutely necessary), as a field procedure, and if the results will not influence the course of treatment or the decision to refer.
Ultrasonography of the equine abdomen is very valuable in horses with colic. Ultrasonography is useful for diagnosis of intestinal strangulation (distended, thick-walled bowel), peritonitis (increased volume of peritoneal fluid and decreased intestinal motility), intussusceptions, displacements, renosplenic entrapment of the large colon, peritoneal effusion, jejunojejunal intussusception, ileocecal intussusception, cecocolic and cecocecal intussusceptions, diaphragmatic hernia, cholelithiasis, ruptured bladder, ascarid impactions, inguinal and scrotal hernias, and abdominal neoplasia.
The purposes of referring a horse to a surgical facility are: 1) to place the horse in an environment where aggressive and intensive treatment can be applied BEFORE the horse’s condition begins to deteriorate; 2) to place the horse in a facility where longterm medical therapy can be applied (as for impaction colic or enteritis); and 3) to place the horse in a facility where it can be monitored continuously. If surgery is needed, its goal is to correct the primary problem BEFORE the horse develops irreversible changes in its intestine or in other organs.
CLINICAL DIAGNOSIS
Assessment of the horse with colic requires an overall impression of the horse’s physical status, without emphasis on any one abnormality, but with due regard for all clinical signs and physical examination findings. In the author’s experience, pain, cardiovascular status, and abdominal distension, alone or in combination, provide the most apparent and sensitive measures of the severity of colic.
Response to analgesics, such as flunixin meglumine or xylazine, is extremely important. An unsatisfactory response, such as a heart rate that remains at or above 48 beats per minute, in spite of an initial decrease, and continued signs of pain, warrants referral and, if needed, surgery. Rectal examination findings can be helpful if positive, but not if negative.
Pain and abdominal distension are marked in horses with large colon volvulus and these horses need prompt surgery. However, other colonic diseases can be less obvious and can have pain of variable intensity. Small intestinal diseases can start with severe pain and no distension in an adult and then the degree of pain decreases as the horse develops endotoxic shock. The goal is to refer the horse before this stage is reached. Preoperative prediction of a small versus large intestinal lesion is highly successful, but identification of the specific intestinal lesion is difficult.
