Canine Influenza Information and Prevention

civ

Canine influenza (CI, or dog flu) in the U.S. is caused by the canine influenza virus (CIV), an influenza A virus. It  is highly contagious and easily spread from infected dogs to other dogs through direct contact, nasal secretions (through coughing and sneezing), contaminated objects (kennel surfaces, food and water bowls, collars and leashes), and by people moving between infected and uninfected dogs. Dogs of any breed, age, and sex or health status are at risk of infection when exposed to the virus.

Unlike seasonal flu in people, canine influenza can occur year round. So far, there is no evidence that canine influenza infects people. However, it does appear that at least some strains of the disease can infect cats.

Canine influenza symptoms and diagnosis 

CIV infection resembles canine infectious tracheobronchitis (“kennel cough”). The illness may be mild or severe, and infected dogs develop a persistent cough and may develop a thick nasal discharge and fever. Other signs can include lethargy, eye discharge, reduced appetite, and low-grade fever. Most dogs recover within 2-3 weeks. However, secondary bacterial infections can develop, and may cause more severe illness and pneumonia. Anyone with concerns about their pet’s health, or whose pet is showing signs of canine influenza, should contact their veterinarian.

CIV can be diagnosed early in the illness (less than 4 days) by testing a nasal or throat swab. The most accurate test for CIV infection is a blood test that requires a sample taken during the first week of illness, followed by a second sample 10-14 days later.

Transmission and prevention of canine influenza

Dogs are most contagious during the two- to four-day incubation period for the virus, when they are infected and shedding the virus in their nasal secretions but are not showing signs of illness. Almost all dogs exposed to CIV will become infected, and the majority (80%) of infected dogs develop flu-like illness. The mortality (death) rate is low (less than 10%).

Lange Animal Clinic veterinarians in Pekin, IL strongly suggest the following items to significantly reduce the spread of canine influenza:

  • Avoiding taking your dog to dog parks, social events, and boarding. Avoid interaction with other dogs to minimize the possibilities of being exposed to the virus. 
  • Isolating ill dogs as well as those who are known to have been exposed to an infected dog and those showing signs of respiratory illness.
  • Good hygiene and sanitation, including hand washing and thorough cleaning of shared items and kennels, also reduce the spread of canine influenza.
  • Use disinfectants when cleaning around the house and make certain to safely sterilize dog supplies such as food bowls, dog toys, and bedding.

There are vaccines against the H3N8 strain of canine influenza, which was first discovered in 2004 and until 2015 was the only strain of canine influenza found in the United States. However, a 2015 outbreak of canine influenza in Chicago was traced to the H3N2 strain – the first reporting of this strain outside of Asia – and it is not known whether the H3N8 vaccine provides any protection against this strain. The CIV vaccination is a “lifestyle” vaccination, recommended for dogs at risk of exposure due to their increased exposure to other dogs – such as boarding, attending social events with dogs present, and visiting dog parks.


For over 45 years, Lange Animal Clinic has provided veterinary services in Pekin, IL and the surrounding areas for over three family generations. Our expert staff of Veterinarians, Veterinary Technicians, and Veterinary Assistants are trained to ensure the best quality medical care for your beloved pets-whether it be as a routine medical examination to more complicated surgical procedures. We are a small companion animal clinic providing services for dogs, cats, and exotic pets.

Dr. Colleen O’Rourke, owner and senior Doctor of Veterinary Medicine, takes great pride in making certain that every patient’s experience is handled with the utmost care, compassion, and economically in the best interests of our clients. Visit us at www.langeanimal.com.  

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