I have been an in-home dog sitter for five years and until the 2017/2018 canine influenza season I had never been asked by one of my pup parents about the dog flu; its prevalence, seriousness, or how contagious it is. So, I did a bit of research and this is what I found.
(1) THE VIRUSThe virus that causes dog flu, Influenza Type A (H3N8), was first identified in Florida in 2004 and was related to the equine virus that was circulating among American horses...interesting! Another virus—H3N2, of bird origin—first appeared in Chicago in 2015 and spread quickly to other states. This seems to be the one causing the most concern in the pet community at this time. Bird virus's are some yucky stuff, in dogs and humans! Check out this graph, the first shows where the flu first appeared in 2007 and how widespread it is now. Yikes!
(2) GOOD NEWSMost dogs have a mild form of the flu. I reached out to my veterinarian at Adobe Animal Hospital in Los Altos and she told me that 90-95% of pups who get the virus will fight it on their own without medical intervention. Yay!
(3) SYMPTOMSThe symptoms of the mild form of the virus are a dry or moist cough, sometimes nose or eye discharge (sometimes green), may have fever and symptoms that will last 10-30 days. I know, not very helpful, in fact I might think my dog has allergies with those symptoms. There are some other symptoms that may include malaise/lethargy and fever. The symptoms of the severe form of the flu are much like the human flu and include sudden and severe onset, high temperature, 104+, and serious respiratory problems. Here is some great guidance on How to check your dog's temperature at home.
(4) RISKYThose at highest risk are the very young, the very old and for those at any age in-between who visit dog parks, go to boarding facilities, or who socialize in any highly populated pup areas. If your pup falls into one of these categories, get the flu vaccine, it is a two shot process.
(5) TREATMENT"The mild form is usually treated with cough suppressants. Antibiotics may be used if there is a secondary bacterial infection. Rest and isolation from other dogs is also important. The severe form needs to be treated aggressively with a broad spectrum of antibiotics, fluids and other general support treatments. Hospitalization and isolation are necessary until the dog is stable." PetMD
My favorite websites for information on canine influenza...