Small colon intussusception in a mare managed with a diverting colostomy.

This study discusses a case of Type 4 rectal prolapse in a Thoroughbred mare, which was initially treated through resection and anastomosis, and then through an exploratory laparotomy and diverting colostomy following a deterioration in the horse’s condition.

Objective and Background

• The research delves into a case study of a 4-year old Thoroughbred mare, experiencing a type 4 rectal prolapse, which is a condition where the peritoneal rectum or small colon protrudes through the anus.
• Rectal prolapse is acknowledged in all species of domestic animals, usually occurring due to conditions that cause tenesmus, such as parturition.
• The prognosis for animals undergoing types 3 and 4 prolapse is generally poor.

Initial Treatment

• The referring veterinarian initially attempted to replace the prolapse under general anesthesia. Due to the edema of the prolapsed bowel, it was challenging, so around 2 meters of the protruding bowel was resected (removed) and anastomosed (rejoined).
• Post-operative treatment for the mare included prophylactic antibiotics and pain relievers to manage the mild abdominal pain. Nevertheless, her complications persisted.

Deterioration and Further Diagnosis

• Subsequently, the mare’s condition deteriorated, becoming restless with additional physical symptoms and signs of gastrointestinal stasis.
• Laboratory tests revealed a leukopenia (a decrease in the number of white blood cells) and lymphopenia (a lower-than-normal lymphocyte count) along with marked haemoconcentration (an increase in the concentration of cells and solids in the blood).
• Results of an abdominal paracentesis indicated a purulent inflammatory exudate, leading to a preliminary diagnosis of acute, diffuse peritonitis, probably stemming from a leaking anastomosis.

Secondary Treatment

• A decision was made to perform an exploratory laparotomy to better understand the health status of the distal colon and examine the anastomosis further.
• This procedure, being a type of surgery, was performed under tranquilization and general anesthesia.