Disease progression, pathologic, and virologic findings of an equine influenza outbreak in rescue donkeys.

BACKGROUND: Equine influenza virus is a common cause of respiratory disease in equids. Few reports describe clinical presentation and disease progression in donkeys. HYPOTHESIS/OBJECTIVES: Describe the clinical and diagnostic findings, outcome, and pathologic lesions associated with influenza pneumonia in donkeys. ANIMALS: Thirteen unvaccinated donkeys ranging from 1 week to 12 years of age and sharing clinical signs and exposure history. METHODS: Retrospective case series. Medical records from June to July 2020 at the Colorado State Veterinary Teaching Hospital and collaborating referring veterinary practices were reviewed. The diagnosis was confirmed by molecular testing, virus isolation, and partial genetic and phylogenetic analysis of the virus. RESULTS: Survival in donkeys <1 year old was 16.6% (1/6) whereas survival in animals >1 year of age was 85.7% (6/7). Hemagglutinin gene sequencing and phylogenetic analysis confirmed a contemporary clade 1 Florida sublineage H3 virus as the causative agent. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinical signs of equine influenza virus infection in donkeys are similar to those observed in horses. Prognosis for survival generally is good, but deaths have been observed especially in foals born to seronegative dams. This finding emphasizes the importance of prenatal vaccination protocols in all equids, including donkeys.

Ruptured hepatic artery aneurysm in a domestic yak.

A 19.5-y-old, male domestic yak ( Bos grunniens) with a history of sudden unexpected death was submitted for autopsy. The yak had hemoabdomen, and a large blood clot was attached to the liver and forestomachs. The hepatic artery had a saccular aneurysm with a 1-cm tear. The arterial wall at the site of the rupture was thin, and the luminal surface was roughened with yellow streaks. The arterial wall adjacent to the rupture was thickened, white, firm, and less elastic than normal arterial walls. Cause of death was concluded to be acute exsanguination. Similar cases with sudden death have been reported in domestic cattle and humans. No risk factors, such as nutritional deficiencies, genetic predisposition, or blunt trauma, were identified in this case, and there was no gross or histologic evidence of generalized vascular disease.