Canine Influenza

Canine influenza, also called dog flu, is a newly recognized disease that is most frequently diagnosed in dogs housed in group settings (e.g., shelters and racing colonies) but can affect individual pets as well. The disease is caused by a highly contagious virus that can be transmitted through direct contact with sick animals or with objects and environments contaminated with their bodily fluids. Canine influenza is similar in many ways to human flu, although dogs and people cannot pass their forms of the disease to each other.




Common symptoms of dog flu include coughing, a runny nose, lethargy, loss of appetite, and a fever. These clinical signs are similar to those caused by many canine respiratory infections. Identifying which pathogen is involved is not always necessary because most cases resolve with similar treatment regardless of the underlying cause. Immunological testing is available if a definitive diagnosis of canine influenza becomes necessary. Chest x-rays and routine blood work are also frequently run to determine the severity of the disease and plan appropriate treatment.




Most cases of canine influenza will resolve with symptomatic treatment and supportive care. More severely affected dogs may require hospitalization, fluid therapy, medications to suppress high fevers, and antibiotics if a secondary bacterial pneumonia develops. Canine influenza infections can be fatal in rare instances, but most dogs recover over the course of a few weeks. A vaccine to prevent dog flu is under development but is not yet available.


Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008