Adenovirus Infection and Salmonellosis in a Group of Laboratory-Housed Corn Snakes (Pantherophis guttatus)
A group of 18 juvenile captive-bred corn snakes (Pantherophis guttatus) was quarantined at the USGS-National Wildlife Health Center. Upon arrival, several of the snakes exhibited intermittent vomiting and anorexia. One individual with persistent vomiting was treated with oral metronidazole, oral electrolyte solution, nutritional support, and subcutaneous fluids. Cryptosporidium sp. was not detected by microscopy or PCR from gastric lavage samples. The snake died 1 mo later; necropsy findings included hepatic and intestinal necrosis, with basophilic to amphophilic intranuclear inclusions found within epithelial cells throughout the alimentary tract. PCR and sequencing confirmed the presence of snake adenovirus 2 within the liver. In the following month, two additional snakes had intermittent regurgitation and anorexia, poor growth, and died despite treatment with antibiotics, nutritional support, and subcutaneous fluids. On necropsy, both snakes were diagnosed with systemic salmonellosis, based upon histologic lesions and isolation of Salmonella from the liver. These snakes also had similar intranuclear inclusions within the gastrointestinal tract and adenovirus was confirmed by PCR. In the first of these three cases, snake adenovirus 2 was the only pathogen found and appeared to be a contributing factor in the death of the snake. Salmonellosis was the likely cause of death in the subsequent cases, but adenoviral infection may have increased susceptibility to this opportunistic pathogen. Adenoviral infection has been previously described in several species of snakes, including corn snakes.4,5 This case report corroborates a retrospective study by Garner et al., showing that snake adenovirus 2 has the potential to act as a primary pathogen or contribute to debilitation and secondary septicemia in colubrids.1 Although it is commonly found in the gastrointestinal tract of healthy snakes, Salmonella may cause severe disease and death in the face of adenoviral co-infection.2,3
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