One of the questions that I get asked repeatedly is whether or not to vaccinate for canine influenza, and typically, I say no except in occasional situations. When I was reading the front page of the Veterinary Information Network last week, I came across an article that was talking about how worrisome canine flu is, and I read it. Although the article didn’t really change my opinion, I thought it was interesting enough to serve as the inspiration for this week’s blog.
Canine influenza is a highly contagious respiratory infection caused by Influenza Type A virus. The H3N8 strain was first identified in 2004. The current outbreak is caused by the H2N2 strain, and it is closely associated with a strain circulating in China and South Korea.
Two forms of the disease are seen. With the mild form, dogs often present with a soft, moist cough that persists for 10 – 30 days, and some dogs will present with a dry cough that sounds like the typical “kennel cough.” Typically, these dogs will improve with or without therapy, and treatment doesn’t alter the course or duration of illness.
With the severe form of disease, dogs present with high fevers (104 – 106°F) and pneumonia. Some of these dogs will even be coughing blood. These dogs have a rapid
onset of clinical signs, and they can die within 4 – 6 hours of presentation. Mortality can range from 5 – 8% in certain groups at high risk, whereas the overall mortality is usually less than 1%.
With the mild form, supportive therapy is recommended. With the severe form, more aggressive supportive therapy is required with fluids and broad-spectrum antibiotics to prevent secondary bacterial infections. No reports are available on the use of Tamiflu®, but it may speed up recovery.
Canine influenza virus is spread most easily in crowded/high-population settings such as shelters, boarding centers, dog parks, pet stores, dog shows, grooming facilities, and veterinary hospitals.
If your dog has potentially been exposed and begins coughing, you should call your veterinarian before just showing up, and you may even want to go without your dog on your initial visit for this problem, describing clinical signs or showing a video of the dog’s cough. When your dog arrives, he/she will likely be taken to the clinic’s isolation ward to decrease the risk of spread, and hospital personnel will wear protective clothing as well.
Vaccines are available for both the H3N8 strain as well as the H2N2 strain, and a bivalent vaccine is available that protects against both strains. None of these vaccines are considered “core” vaccines, and they will not prevent infection. However, vaccination will decrease the severity and duration of infection, and in certain dogs with greater risk factors (older age, frequent visits to high risk locations, or lifestyle – i.e., show dogs traveling across state lines), vaccination should be considered and discussed with your veterinarian.
In closing, the article I mentioned showed a map, and if you look at it, no cases of canine flu have been reported yet in Oklahoma although our neighbors to the south have seen a significant number of cases. So, if you are planning on traveling this summer to an affected area (or if you are worried about your dog being at high risk for flu or its complications), you should contact your veterinarian to discuss vaccination. As I said earlier, most dogs don’t need it, but if your dog is at risk, protection through vaccination is better than disease.
For more information regarding dog flu and to view the map being referenced, please go to the original web article on VIN's website here.