Abstract Title
The Clinical Presentation and Necropsy Findings of Highly Pathogenic Avian Influenza Virus Infection in North American Raptors
Abstract
The Raptor Center (TRC) at the University of Minnesota is the largest raptor rehabilitation center in the United States, admitting over 1,000 wild raptors annually. From March 28, 2022 through December 31, 2023, TRC admitted 223 raptors representing 12 species that were confirmed positive for highly pathogenic avian influenza (HPAI; strain EA/AM 2.3.4.4 H5N1) via polymerase chain reaction (PCR) testing. The clinical signs observed in positive birds were systemically evaluated in order to characterize the clinical disease presentation of this virus in North American raptor species. The vast majority of birds admitted with the virus were exhibiting severe neurologic signs or were deceased, though there was a small population of birds that were not flagged as HPAI suspects at the time of admission. Data analysis is currently in progress, and includes assigning severity scores to neurologic exam findings which can be used to provide an objective assessment of the clinical presentation of this virus in raptors. A subset of raptors had complete post-mortem examinations performed. In the bald eagles (Haliaeetus leucocephalus, n=6), red-tailed hawks (Buteo jamaicensis, n=9) and great horned owls (Bubo virginianus, n=8) that were necropsied, gross lesions were uncommon, while histologic lesions of inflammation in multiple organs including the brain, heart, and pancreas were common. These necropsy findings correlated with the observed clinical signs to create a more complete picture of the disease pathogenesis.
Co-Author(s)
Kelsey Rayment, DVM, The Raptor Center, College of Veterinary Medicine, University of Minnesota
Annette Ahlmann-Garcia, DVM, MS, The Raptor Center, College of Veterinary Medicine, University of Minnesota
Carol Cardona, DVM, PhD, Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota
Kristelle Mendoza, Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota
Arno Wuenschmann, Dr vet med, DACVP, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota
Victoria Hall, DVM, MS, DACVPM, Oiled Wildlife Care Network, Karen C. Drayer Wildlife Health Center, School of Veterinary Medicine, University of California Davis
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds