Alcelaphine gammaherpesvirus 1-induced malignant catarrhal fever in a Watusi (bos taurus africanus) steer in a North American game park

Authors: BILDFELL, R - Oregon State University; Li, Hong; ALCANTAR, B - Wildlife Safari; Cunha, Cristina; BRADWAY, D - Washington State University; THOMAS, K - Wildlife Safari

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2016
Publication Date: 5/26/2017
Citation: Bildfell, R.J., Li, H., Alcantar, B., Cunha, C.W., Bradway, D.S., Thomas, K.S. 2017. Alcelaphine gammaherpesvirus 1-induced malignant catarrhal fever in a Watusi (bos taurus africanus) steer in a North American game park. Journal of Veterinary Diagnostic Investigation. https://doi.org/10.1177?1040638717708392.
DOI: https://doi.org/10.1177?1040638717708392

Interpretive Summary: Wildebeest-associated malignant catarrhal fever (WA-MCF) is a frequently fatal disease of domestic and exotic ruminants caused by alcelaphine herpesvirus 1 (AlHV-1), a herpesvirus from wildebeest. The disease sporadically occurs in North America where wildebeest are present, especially in game farms and wildlife conservations. Diagnosis of WA-MCF in most cases in the past was based on clinical signs, histopathological, and serologic findings plus direct or indirect epidemiological evidence of exposure to wildebeest, which sometimes can be a problem in identification of the causative virus, especially when multiple MCF viruses are present. This report we describe the diagnosis of clinical WA-MCF in a Watusi steer held in an Oregon drive-through game park using a multiple PCR specific for all MCF viruses known to cause clinical disease. A 10 year-old Watusi steer housed at a drive-through game park in Winston, Oregon developed severe clinical illness. Clinical and histopathplogical findings were suggestive of MCF. DNA sample obtained from the animal was positive for AlHV-1, but negative for other MCF viruses, as tested by the multiplex PCR. Differential diagnosis performed for several other infectious diseases were negative. This was the first diagnosis of clinical WA-MCF at the park. Although this disease is sporadic in North America, it must be considered as a differential diagnosis for febrile illness with ulcerative oral lesions in ruminants.

Technical Abstract: A 10 year-old Watusi (Bos taurus africanus) steer housed at a drive-through game park in Winston, Oregon developed severe clinical illness including: fever, marked nasal discharge, injected scleral and conjunctival membranes, plus oral hemorrhages and erosions. The animal responded poorly to supportive treatment and was euthanized. Additional gross findings at post mortem examination included papules and erosive lesions on the tongue, a hemorrhagic large intestine and multifocal cardiac hemorrhages. Histopathologic findings included multifocal lymphoplasmacytic vasculitis plus fibrin exudation in heart and tongue. Total DNA obtained from the splenic samples were positive for alcelaphine herpesvirus 1 (AlHV-1) as tested by a multiplex PCR for malignant catarrhal fever (MCF) viruses. The AlHV-1 diagnosis was further confirmed by amplification and sequencing of a viral DNA polymerase gene fragment, which was identical to AlHV-1 sequences in Genbank. Differential diagnosis performed for several other infectious diseases were negative. This was the first diagnosis of clinical wildebeest-associated MCF on these premises although wildebeest have been held at the park for over 25 years. This disease is sporadic in North America and must be considered as a differential diagnosis for febrile illness with ulcerative oral lesions in ruminants.