TitlePathology and viral antigen distribution of lethal pneumonia in domestic cats due to pandemic (H1N1) 2009 influenza A virus.
Publication TypeJournal Article
Year of Publication2010
AuthorsLöhr CV, DeBess EE, Baker RJ, Hiett SL, Hoffman KA, Murdoch VJ, Fischer KA, Mulrooney DM, Selman RL, Hammill-Black WM
JournalVet Pathol
Date Published2010 May
KeywordsAnimals, Antigens, Viral, Cat Diseases, Cats, Disease Outbreaks, Fatal Outcome, Female, Influenza A Virus, H1N1 Subtype, Lung, Male, Oregon, Orthomyxoviridae Infections, Pneumonia, Viral

A novel swine-origin H1N1 influenza A virus has been identified as the cause of the 2009 influenza pandemic in humans. Since then, infections with the pandemic (H1N1) 2009 influenza virus have been documented in a number of animal species. The first known cases of lethal respiratory disease associated with pandemic (H1N1) 2009 influenza virus infection in house pets occurred in domestic cats in Oregon. A 10-year-old neutered domestic shorthair and an 8-year-old spayed domestic shorthair died shortly after developing severe respiratory disease. Grossly, lung lobes of both cats were diffusely firm and incompletely collapsed. Histologically, moderate to severe necrotizing to pyonecrotizing bronchointerstitial pneumonia was accompanied by serofibrinous exudation and hyaline membranes in the alveolar spaces. Influenza A virus was isolated from nasal secretions of the male cat and from lung homogenate of the female cat. Both isolates were confirmed as pandemic (H1N1) 2009 influenza virus by real-time reverse transcriptase polymerase chain reaction. With immunohistochemistry, influenza A viral antigen was demonstrated in bronchiolar epithelial cells, pneumocytes, and alveolar macrophages in pneumonic areas. The most likely sources of infection were people in the household with influenza-like illness or confirmed pandemic (H1N1) 2009 influenza. The 2 cases reported here provide, to the best of the authors' knowledge, the first description of the pathology and viral antigen distribution of lethal respiratory disease in domestic cats after natural pandemic (H1N1) 2009 influenza virus infection, probably transmitted from humans.

Alternate JournalVet. Pathol.
PubMed ID20382823
PubMed Central IDPMC4165647
Grant ListP30 ES000210 / ES / NIEHS NIH HHS / United States