Hepatitis and Enteritis Caused by a Novel Herpesvirus in Two Monitor Lizards (<i>Varanus</i> Spp.)

Abstract

Reported cases of herpesvirus-induced disease are uncommon in most species of reptiles, with the majority of reports in chelonians. Two monitor lizards (Varanus spp.) presented for postmortem examination at the Veterinary Medical Diagnostic Laboratory at the University of Missouri. Tan, 1-2-mm foci were grossly visible on the mucosal surface of the intestine and in the liver. Microscopically, there was multifocal necrosis in the lamina propria of the small intestine and in the liver. Many of the degenerate cells contained large, eosinophilic intranuclear inclusions. Enveloped icosahedral virions consistent with herpesvirus were detected by electron microscopy. A 180-bp DNA fragment was amplified by polymerase chain reaction from samples of small intestine and liver using primers that targeted a portion of the herpesvirus DNA polymerase gene. The sequence of the fragment was determined to be most closely related to Varanid herpesvirus 2 (80% nucleotide identity, 82% amino acid identity). Based on histological and molecular findings, a novel pathogenic herpesvirus of lizards in the family Varanidae is proposed.