Serologic prevalence of antibodies against canine influenza virus (H3N8) in dogs in a metropolitan animal shelter.

OBJECTIVE: To determine the prevalence of exposure to canine influenza virus (CIV) in dogs in a metropolitan animal shelter.
DESIGN: Serologic survey. ANIMALS: 74 dogs. PROCEDURES: Dogs were randomly selected from the canine shelter population. A physical examination was performed, and blood samples were obtained and submitted for serologic testing for the detection of antibodies against CIV. Logistic regression analysis was performed to evaluate the association of factors (body condition score, nasal discharge, coughing, rectal temperature, number of days in the shelter, and relinquished vs stray) with positive results.
RESULTS: 31 of 74 (42%) dogs were seropositive for antibodies against CIV. Positive serologic test results were detected for 6 of 39 (15%) dogs housed in the shelter for <or= 7 days and for 25 of 35 (71%) dogs housed in the shelter for > 8 days. Number of days in the shelter was the only factor significantly associated with positive serologic test results. For every 3 days in the shelter, the odds of a positive serologic test result increased significantly by 2.2 (95% confidence interval, 1.5 to 3.4). CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of the results suggested that more dogs were exposed to CIV in the shelter than were exposed in the urban environment. This has serious implications for design and management of animal shelters.