Gastric cryptosporidiosis in a captive Pacific gopher snake (Pituophis catenifer): Case #11 at 56th AAVLD Diagnostic Pathology Slide Seminar

History/signalment: A 20 year old, 1.70 kg, 1.88 cm long, female Pacific gopher snake (Pituophis catenifer) was presented to CAHFS for a full diagnostic work-up. The snake had been housed at a non-for-profit museum in California. It had a history of recurrent mid-coelomic swelling. Cryptosporidia were detected in the feces and it was euthanized due to epizootic concerns. Gross pathology: The gastric wall was diffusely thickened with the mucosal surface diffusely rugose and multifocally reddened. The liver had multifocal, random, pinpoint, golden foci. The intestines were moderately dilated by moderate amounts of mucinous material admixed with ingesta. The rectum contained large amounts of semisolid viscous feces. Histopathology: Stomach: the gastric wall was markedly thickened. The mucosa was expanded by multifocal to diffuse, severe hypertrophy and hyperplasia of the mucus neck cells that often replaced the granular cells of gastric glands. Lining the mucosal surface, the luminal glandular epithelium, and free within the lumen of the gastric glands, were myriad 3-7 μm diameter, round, pale amphophilic protozoa with basophilic nuclei, consistent with Cryptosporidium sp. Multifocally the lamina propria, submucosa and tunica muscularis contained few lymphocytes and plasma cells. Within the lumen and on the surface of the gastric mucosa there were few sloughed epithelial cells. The mucosa was multifocally mildly eroded. Liver: Diffusely hepatocytes showed severe, macro- and micro- vacuolation; most hepatocytes contained many fine brownish Perl’s blue (iron) positive hemosiderin granules. Kidney: Many tubular epithelial cells contained hemosiderin granules. Morphologic diagnoses: 1. Gastric hypertrophy and hyperplasia, chronic, diffuse, severe, with myriad free and apically attached protozoa, consistent with Cryptosporidium sp. 2. Hepatocellular hemosiderosis, diffuse, marked with diffuse fatty lipidosis. 3. Renal hemosiderosis, diffuse, marked.Etiologic diagnosis (etiology): Gastric cryptosporidiosis (Cryptosporidium serpentis).Comments: Gastric hypertrophy/hyperplasia, although not pathognomonic, is a lesion often associated with Cryptosporidium infection in snakes. C. serpentis is a snake specific species, rather than a species associated with consumed infected prey or other reptile species, and was possibly introduced to the collection by a new acquisition. The diagnosis allowed appropriate health management decisions to be taken for the rest of the reptile collection, and alleviated epizoonotic and public health concerns.