Aflatoxicosis in African greater cane rats (Thryonomys swinderianus)

Aflatoxicosis is a widespread problem in captive animals fed on stored food and has been reported in various animals both domestic and wild. This report documents the clinicopathologic, microbial diagnostic findings and therapeutic regime for a study on the presentation, management, and outcome of aflatoxicosis in greater cane rats.

A total of 65 greater cane rats suspected to be exposed to the toxin were examined clinically along with their environment. Feed samples, recently deceased carcasses and some moribund carcasses were collected for the study. Carcasses were subjected to gross and histopathologic investigations while feed and organs were subjected to microbiological investigations.

Gross lesions included hepatic lipidosis with ecchymotic hemorrhages, distended gallbladder, and renomegaly with ecchymosis among others. Histopathology revealed loss of hepatocellular architecture with massive centrilobular hepatocyte necrosis and diffuse steatotic damage characterized by macrovacuoles. Other histologic findings included pulmonary congestion, moderate renal tubular degeneration, and necrosis of epithelial tubular cells. Aspergillus flavus was isolated from the feed and ingesta. Total aflatoxin detected in feed sample was found to be over 400 ppm. Klebsiella species, Staphylococcus species, and Bacillus species were isolated from the liver and intestinal content. Management was attempted using Fungizal^® (Avico, Jordan) (which contains Thymol, benzoic acid, sorbic acid, and kaolin) and Orego-Stim^® (Saife, USA) (which contains carvacrol and thymol) which were instituted in feed and Superliv^® (Ayurvet, India) (polyherbal) liquid was instituted in water for 5 days at manufacturers' dosage. All clinical signs disappeared, and no more deaths were recorded following management.

This report concludes that aflatoxicosis causes severe mortality in greater cane rats and can be prevented and managed successfully.