Canine Influenza

What is Canine Influenza?:

Canine influenza is a new, highly contagious strain of the influenza A virus known as H3N8 that causes respiratory illness in dogs.  Severity of infection ranges from mild respiratory infection in some dogs to pneumonia and death in a small number of cases.  The virus was first reported in Florida in March 2003 and has since been reported in 30 states, including New Hampshire.  Canine influenza virus only affects dogs. 

How contagious is Canine Influenza?:

Because this is a  relatively new virus, and dogs have no natural immunity to it, virtually 100% of dogs are susceptible to infection and 80% of infected dogs show signs of the disease.  Even dogs that show no signs of infection, but have been exposed to the virus, can spread canine influenza to other dogs.  Influenza is spread through direct contact with infected pets,  through the air from cough and sneezing, and from contact with infected surfaces.  The presence of one infected dog can rapidly spread the virus to every dog it is in contact with, or has contact with the environment it has infected.

Symptoms, Severity and Diagnosis:

The most common sign of canine influenza is a persistent cough.  Approximately 80%  of  dogs showing signs of canine influenza will have mild symptoms including low grade fever, nasal discharge, lack of energy and appetite and a cough that can last for up to a month.  Approximately 20% of dogs showing signs of infection will have more severe symptoms which may include high fever (104-106 F) and pneumonia which has lead to death in some cases.

Because it is similar to the more common Bordetella, or "kennel cough", it is hard for veterinarians to diagnose which illness your pet has upon initial presentation.  Often it is not until the illness becomes unusually severe or lasts unusually long that canine influenza may be suspected.

Prevention of Canine Influenza:

Vaccination:.  A new vaccine has been developed that significantly reduces the severity of influenza and the length of time that an infected dogs is sick. The vaccine is administered in 2 doses, 2-4 weeks apart and annually thereafter.  Vaccination is recommended for all dogs that are boarded, attend doggie day care, dog parks, or any situation where contact with other dogs occurs.