What Pet Owners Need to Know About the Dog Flu


There have been 5 recent confirmed cases of the dog flu, or canine influenza, in Texas.  This article has information that pet owners need to know about the dog flu to prevent the infection in pets.


The Spread of Canine Influenza

Canine influenza, or the dog flu, is a highly contagious viral infection affecting dogs and cats.  Influenza viruses belong to the family Othomyxoviridae.  There have been two strains of canine influenza identified in the United States, H3N8 and H3N2.  Influenza viruses are able to evolve and change and give rise to new strains that can infect different species.  The H3N8 influenza was first identified in dogs in the United States in 2004 and the H3N2 influenza was first identified in dogs in the United States in 2015.  Cats have also been infected with the canine influenza virus.  There have not been any reports of humans becoming infected with canine influenza.  In May of 2017, canine H3N2 influenza was diagnosed in dogs in Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana, and Illinois.  Read more about the history of the virus through the American Veterinary Medical Association.


Canine Influenza Symptoms

Canine influenza is transmitted through respiratory secretions from coughing, barking, and sneezing.  It can also spread by indirect contact with the virus on objects such as dog bowls, or human hands.  The virus can remain contagious in environments for 2 days.  Symptoms will arise in dogs between 2 and 8 days after exposure in most cases.  Most dogs exposed to canine influenza will become infected however up to 20% will not have any symptoms.  Symptoms can include a cough, nasal discharge, sneezing, lethargy, eye discharge, fever, and loss of appetite.  Secondary bacterial infections can cause further respiratory disease.  Some dogs can be affected more severely and can develop pneumonia.  Cats infected with canine influenza can also develop respiratory symptoms similar to dogs.  The virus can be diagnosed by laboratory testing as well as the clinical signs.


Treatment of Canine Influenza

Treatment of canine influenza involves supportive care.  Pets who are severely affected or immune compromised will often need to be hospitalized for more intensive care.  Fluids are needed to support hydration and antibiotics are often needed to treat secondary bacterial infections.  Anti-inflammatory medication may be needed to reduce high fevers.  10% of reported dogs infected with canine influenza passed away.  Pets who have been infected with canine influenza should be isolated from other pets for 4 weeks to prevent transmission.


Prevention of Canine Influenza

Vaccines are available for both the H3N8 and the H3N2 strains of canine influenza.  Dogs who have more contact with other dogs including doggy daycare, dog parks, boarding, or traveling, are at higher risk for being exposed to canine influenza.  You should discuss your dog’s risk level with us or your regular veterinarian to decide if vaccination is best for your dog.  At Spring Branch Veterinary Hospital we carry the vaccine that covers both the H3N8 and the H3N2 canine influenza strains.  Dogs who have not previously received the vaccine should be boostered in 3-4 weeks with a second vaccine.  The vaccine is then recommended yearly depending on the risk.  Dogs who do not come into contact with other dogs frequently are less likely to be exposed to the virus.


There have been 5 recent canine influenza cases reported in Texas.  Please call us if you would like more information or to discuss vaccinating your dog against this canine influenza virus.  830-438-7800. 


Read here for more information on Canine Influenza.

Megan Hughes, DVM

Spring Branch Veterinary Hospital