Fatal purulent diverticulitis associated with Citrobacter freundii in a loggerhead sea turtle (Caretta caretta): clinical and diagnostic aspects

Abstract

Although digestive system diseases are important causes of sea turtle strandings, cases of diverticulitis affecting the digestive tract of loggerhead sea turtles (Caretta caretta) are very rare. We describe morphologically and microbiologically an unusual case of fatal purulent intestinal diverticulitis in a stranded subadult loggerhead. When stranded, physical examination revealed large amounts of algae and epibionts, indicating that the turtle had been floating on the surface for a long time. Imaging diagnostic techniques included X-ray exploration, fluoroscopy, computed tomography, and endoscopy. Atelectasis (left lung) and severe dilation of the gastrointestinal tract together with a mass of different radiodensities were observed. At necropsy, an intestinal diverticulum, 26 cm in diameter, distended by yellow, firm, lamellated, caseous exudate, was observed in the large intestine. Histologically, severe purulent intestinal diverticulitis was diagnosed. The no identification of all layers of the intestinal wall in the diverticulum suggests it was a pulsion diverticulum of probable traumatic origin. The bacteria isolated from the intestinal diverticulitis (Citrobacter freundii and Morganella morganii) exhibited great antibiotic resistance, which is why antibiotic treatments during its stay in the Tafira Wildlife Rehabilitation Center were not effective. Intestinal diverticulitis should be included in the differential diagnosis of gastrointestinal diseases in loggerhead sea turtles.