Hyperkeratotic gastritis in two-toed sloths (Choloepus didactylus) from wildlife rescue

Xenarthran mammals of the suborder Folivora are arboreal species that feed mainly on leaves and Cecropia spp, an abundant plant in the Brazilian Amazon region, is favoured. The stomach of sloths represents 20-30% of their body weight and is adapted to gastric fermentation of plant material. These anatomical and physiological adaptations can be altered by many factors when confined to captivity, which favours fatal gastric conditions. The objective of this study was to describe the gastric anatomopathological lesions in three two-toed sloths (Choloepus didactylus) from a wildlife rescue centre. Necropsy revealed wide variation in the thickness of the gastric mucosa, with large areas having a papilliform appearance. Histologically, hyperkeratinization of the stratified squamous epithelium of the aglandular gastric region and infiltration of lymphocytic and plasmacytic cells were seen. The histopathological diagnosis was chronic hyperkeratotic gastritis, which has not previously been reported in sloths. Repeated exposure to dietary antigens, drugs, chemicals, toxins or infectious agents can initiate allergic or immune-mediated responses that can ultimately lead to chronic gastritis in these animals.