Recently you may have heard on the news about a viral outbreak of canine influenza in the Orlando area. Many boarding facilities, doggy daycares and dog parks in the region were temporarily closed to control the situation. So how does canine flu affect our canine companions, and what do we need to know?
Canine Influenza (or dog flu) in the U.S. is caused by the canine influenza virus (CIV), an influenza A Virus. There are two known strains of the virus, called H3N8 and H3N2. The current outbreak is caused by the H3N2 strain. 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, sex, or health status are at risk of infection when exposed to the virus, but it is a greater concern for dogs with weak immune systems: puppies, seniors and those with other diseases.
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.
Almost all dogs exposed to CIV will become infected and the majority (80%) of infected dogs develop flu-like illness. 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 fever. Most dogs recover within 2-3 weeks. However, secondary bacterial infections can develop and may cause more severe illness and pneumonia. The mortality (death rate) is low (less than 5%). 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.
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.
The H3N8 strain of canine-influenza was first discovered in 2004 in racing Greyhounds here in Florida 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. Vaccines are available against both strains. The vaccines may not completely prevent infection, but appear to reduce the severity and duration of the illness, as well as the length of time when an infected dog may shed the virus in its respiratory secretions and the amount of virus shed – making them less contagious to other dogs.
We have not seen cases in Melbourne yet, but with it being in Orlando, it is highly likely that we will. We do not consider the canine flu vaccine a necessary “core “vaccine for all dogs, however, you travel a lot and have any sort of exposure to dog parks, boarding and grooming facilities and the like, you may want to discuss with your veterinarian vaccinating your dog as a “lifestyle” preventive health care measure. At our boarding facility we currently do not require the canine flu vaccination, but we do highly recommend it. Two doses are needed to establish immunity and they must be at least two weeks apart, so it takes at least 3 weeks to protect a dog from the disease. If you are planning to board you dog in the next month or so, you should plan to get the vaccines right away.