Successful treatment of elephant endotheliotropic herpesvirus infection in an Asian elephant (Elephas maximus) calf by oral acyclovir medication: Case report

Abstract

Elephant endotheliotropic herpesvirus (EEHV) is a major cause of death in Asian elephant (Elephas maximus) calves. A 2-year, 11-month-old female, captive Asian elephant presented with facial edema and a mild fever. Blood samples were collected and showed EEHV1A positivity with a high viral load by real time PCR. Heterophil toxicity also was reported for the first time in this case. The calf was treated orally with acyclovir, 45 mg/kg tid for 28 days, which reduced the EEHV1A viral load to undetectable levels within 9 days and the calf survived. A successful outcome with oral acyclovir administration provides another and affordable option to treat EEHV hemorrhagic disease in Asian elephants, and one that is easier to administer in untrained calves.

Keywords: Asian elephant; acyclovir; elephant endotheliotropic herpesvirus (EEHV); heterophil toxicity; oral medication.

Fig. 1.

Viral load of an elephant calf during elephant endotheliotropic herpesvirus1A-hemorrhagic disease (EEHV1A-HD) infection and treatment with oral acyclovir (45 mg/kg/d) for 28 days, Note log scale for viral loads. Undetectable viral load was showed in the dot at the baseline. The clinical signs were showed above the figure.

Fig. 2.

Heterophil left-shifting and toxicity with a monocyte and lymphocyte in a blood smear collected, ×40 objective (a, b). A band heterophil that lacked nuclear constrictions and smooth parallel nuclear walls (c, d, e) and a heterophil with moderate cytoplasmic basophilia, ×100 objective (f, g, h). Wright Giemsa stain.