Canine Influenza

Kara M. Burns, MS, MEd, LVT, VTS (Nutrition), Wamego, Kansas

Sign in to Print/View PDF

Canine Influenza

The canine influenza virus (CIV) outbreak, which began at dog shows in Florida and Georgia in early June 2017 and quickly spread to 11 states, has recently been confirmed in Ohio.1-6 The outbreak is expected to continue spreading because of the highly contagious nature of the infection, which is attributable to influenza A virus.3

The contributing CIV strains have been categorized as H3N8 and H3N2. In spring 2015, more than 1000 dogs were affected by influenza in Chicago and the Midwest areas. Within 5 months, the virus had spread to 23 states.7 At the time, the virus H3N8 was believed to be the culprit; however, the true culprit was found to be the H3N2 virus, a new influenza strain currently spreading across the southeast United States.

Editor's Note

This outbreak is expected to spread. For updates and additional information, visit the AVMA website

Veterinary healthcare teams must be vigilant and stay abreast of the latest information about this highly contagious disease (eg, areas affected, prevention, canine influenza treatment protocols where appropriate). Pet owners may be anxious about the potential impact of this disease on the human–animal bond, so veterinary professionals should be prepared to answer their questions and provide guidance.


What signs may be seen in canine flu patients?

Canine influenza can cause8-10:

  • Coughing
  • High fever
  • Lethargy
  • Loss of appetite
  • Nasal discharge

Signs may be more severe in cases caused by the H3N2 virus than those caused by H3N8.7 Additionally, some infected dogs may not show any symptoms, but they can still spread disease.

How is canine influenza transmitted?

CIV is spread through aerosolized respiratory secretions (eg, coughing, barking, sneezing) as well as fomites (ie, contaminated objects [eg, kennel surfaces, food and water bowls, collars, leashes]). CIV can also be transmitted by people moving between infected and uninfected dogs. Veterinary healthcare team members must be vigilant because the virus can remain viable on surfaces for up to 48 hours, clothing for 24 hours, and hands for 12 hours. All dogs are susceptible to infection.10,11 

A CIV outbreak is possible when the virus is introduced to a dog population with limited immunity and frequent close contact. A dog show is an ideal venue for viruses like influenza to spread because just 1 infected dog can cause an outbreak that spreads rapidly. As the dogs return home from the show they begin to break with CIV, which then spreads to other dogs in their area.3,11 

Should dogs be vaccinated?

Veterinary healthcare teams should review the decision to vaccinate based on risk assessment, allowing for the likelihood of patient exposure and the implications of infection.3,8 Consider the following when deciding risk and need for vaccination:

  • Has CIV been confirmed in the area?
  • Will the patient be traveling to an area where CIV is present?
  • Does—or will—the patient have regular contact with many different dogs?
  • Does—or will—the patient have regular interaction with dogs from areas where canine flu may be present?
  • Does the patient’s age or health status (eg, young, old, immunocompromised) increase risk for complications following infection?

What about a cat living in the same household?

H3N2 has caused infection and respiratory illness in cats but less frequently.10 Signs of infection are similar to those seen in dogs.

Communicating with Clients

Clients most likely will have heard of the recent outbreak and be concerned for their own dogs. Educate owners about the increased risks of their dog becoming infected in canine group settings and settings with dog-to-dog contact (eg, dog shows, dog parks, shelters). As families take their dogs on vacation during the summer season, the risk for the spread of CIV increases.

Explaining that the spread of CIV is similar to the spread of human influenza may help owners better understand the risks for their pet. Discuss how people avoid influenza and how similar approaches can be used with dogs with CIV. 

  • Do not allow the dog to have close contact with other dogs or dogs unfamiliar to the family, especially dogs that are sneezing, coughing, or have traveled recently. 
  • Do not allow the dog to share food and water bowls, toys, or blankets with other dogs because these objects could be fomites for pathogens.  
  • Wash or launder items before returning home to help decrease contamination.
  • Owners may act as a fomite—hygiene is of the utmost importance, and owners must pay careful attention to hand hygiene (eg, using hand sanitizer frequently), especially when they touch other dogs. This will help decrease the number of pathogens transmitted to their own dog.

Triaging for the Client Care Team

As confirmed cases in the recent CIV outbreak continue to mount and news of the outbreak continues to spread, the practice team will field more calls from nervous owners regarding CIV. Communicating with clients will be paramount to alleviate their fears. This is a highly contagious virus spread by direct and indirect contact, and the practice team should be prepared to answer questions and advise clients. As always, listening carefully to client questions is key to successful communication. A one-size-fits-all statement may not be the best-case scenario when talking with worried owners. 


If a client says his or her dog is exhibiting signs, tell him or her that the pet should be seen by the veterinarian and practice team immediately. Questions to ask clients who call include:  

  • Has your dog been around other dogs recently?
  • Has your dog traveled recently?
  • Is your dog coughing, sneezing, or experiencing nasal discharge?


Have a plan in place at the practice for handling patients with respiratory signs. To avoid potential exposure to other patients, do not allow these dogs in the waiting room. Each practice will have different capabilities, but consider limiting patients with respiratory signs to 1 examination room and asking these clients to wait in the car until they can be seen or to enter the practice through the side door. 


If a client asks about active CIV cases in the area, tell him or her about any confirmed cases the practice is aware of and share any additional resources. (See Resources.)


If a client asks how to avoid CIV, educate him or her on high risk areas and the signs associated with CIV. Also educate owners about the highly contagious nature of CIV and review the approaches above to help them understand what is needed to avoid the virus. Remember to tie this information to approaches that help avoid the human influenza virus.

Editor's note: This article was updated with additional sources on November 13, 2017.

References and Author Information

Material from Veterinary Team Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

Practice Tools


Client Communication

Veterinary Team Brief delivers practical skills for team-based medicine—with clinical strategies for team training, peer-reviewed credibility, concise content, essential training modules, and easy-to-implement protocols. From the publisher of Clinician's Brief.

© 2018 Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Privacy Policy (Updated 05/08/2018) Terms of Use (Updated 05/08/2018)