Abstract

Orphan manatees can present to rescue facilities a number of problems including malnutrition, dehydration, hypogammaglobulinemia, sepsis, trauma, and enterocolitis. Of the intestinal complications the most severe have included necrotic enterocolitis and pneumatosis intestinalis. Pneumatosis intestinalis is an intramural accumulation of gas in the intestinal wall. It can occur from the stomach to the colon ranging from focal to linear involvement. Etiologies in humans may include bowel necrosis due to bowel ischemia, infarction, necrotizing enterocolitis, neutropenic colitis, volvulus, and sepsis. Pneumatosis can be secondary to mucosal disruption caused by ulceration, mucosal erosion, trauma, perforation, and defects in the intestinal crypts secondary to acute and subclinical enteritis that allows intraluminal bacterial gas to percolate into the bowel wall. Treatment options may include surgical removal of the affected area or complete rest of the intestinal tract with parenteral hyperalimentation. The difficulties utilizing these techniques include malabsorption secondary to extensive bowel loss, and logistic problems with maintenance of sterile intravenous line for extended periods of time in a mobile animal.

Necropsy results of previous cases show a wide variation in the amount of the colon involved although pneumatosis intestinalis can extend from the rectum to, and include, the cecum. A newborn orphan that was presented to SeaWorld developed pneumatosis intestinalis after shedding a substantial amount of its colonic mucosa during therapy. An Internet search for treatment alternatives in human medicine revealed the use of an elemental diet in the improvement of this condition in two affected human individuals. An elemental diet was assembled consisting of Criticare HN, (Criticare HN, Mead Johnson and Co., Evansville, IN 47721), Nutramigen, (Nutramigen, Mead Johnson and Co., Evansville, IN 47721), and medium chain triglycerides. In addition, the manatee was placed on Pepto-Bismol, metronidazole, simethicone, and metoclopramide hydrochloride. After 3 weeks of therapy the radiographic signs of intestinal air were not detectable. The diet was adjusted to reintroduce the typical formula but after two weeks a hemorrhagic colitis developed which responded to antibiotic therapy consisting of gentamycin (2.5mg per kg, PO, TID) with metronidazole (7mg per kg, PO, BID). In 4 days the radiographic signs were again undetectable and therapy was continued for an additional 10 days. Subsequent therapy included seeding the gastrointestinal tract with lactobacillus, fresh feces from an adult manatee, and antifungal agents. At present, the manatee is nursing normally and growing.