First identified in 2004, the H3N8 canine influenza virus is the first known proper flu virus to affect dogs. While dog flu is highly contagious and highly infectious among dogs, it has given neither veterinarians nor dog owners any reason to regard canine influenza as being particularly dangerous or deadly.
The greatest risk for infection is in places with a large number of dogs and heavy turnover, such as boarding facilities and kennels. There is a vaccine for dog flu, but even that is still considered optional for dogs who do not frequent these facilities.
Dog flu is a viral infection that affects the respiratory system of dogs, with symptoms and risk factors that are very similar to kennel cough. Canine influenza virus spreads through the air and by contact with infected objects, so it is most easily contracted in places where a number of other dogs are present.
This includes boarding facilities, kennels, groomers, dog parks, training classes, and, yes, even veterinarian’s offices. Like other infectious diseases, very young puppies, senior dogs, and those with weakened immune systems are at greatest risk.
The newness of canine influenza means that dogs do not have a natural or inherited immunity to it. Any dog who is exposed to the canine influenza virus may contract it, but according to the Centers for Disease Control, some 80 percent of dogs who are exposed will only develop the mild form, which, like human flu, is self-limiting, running its course within two to three weeks.
There are two forms of dog flu, mild and severe. The mild form of dog flu is by far the more common, and it has symptoms that are indistinguishable from most respiratory disorders in dogs. These include coughing, sneezing, and runny noses. A dog with a mild form of the canine influenza virus may even develop a fever, though the fever tends to subside before dog owners even notice.
The danger of the severe form of canine influenza is not from the virus itself, but from the manifestation of secondary bacterial infections such as pneumonia taking hold while the dog is in a weakened state. In addition to coughing, sneezing, and runny noses, dogs with a severe case of flu may have a more insistent fever ranging from 103 to 107 degrees F., difficulty breathing, and, occasionally, a cough that produces blood.
Dogs with mild canine influenza are treated with much the same approach as with humans: to wit, with rest and plenty of fluids, which for dogs means a ready supply of fresh water. In multi-dog households, a sick dog should also be isolated from the others for the duration of the illness. A dog with severe canine influenza will need an accurate diagnosis involving tests of saliva and blood before proceeding to treatment, which may require hospitalization, fluids, and broad-spectrum antibiotics to combat the secondary infection.
A vaccine for the H3N8 canine influenza virus, consisting of two shots administered over the course of three weeks, was approved for use in 2009, but it is still considered optional. Consult with your veterinarian, who will be better equipped to tell you whether the area you live in has a track record of diagnosed dog flu cases. Some boarding facilities and kennels, such as this one in Pennsylvania, have begun to require the vaccination as a prerequisite for a dog’s stay. There are no known side effects from the dog flu vaccine.
While it is highly contagious and infectious between dogs, the canine influenza virus is not a zoonotic disease. There has yet to be a single instance of the H3N8 dog flu infecting any other creature, including humans. Be cautious and practical, though, especially if you have more than one dog. Following routine hygienic practices — washing your hands after touching strange dogs, and regularly cleaning and disinfecting your dog’s bedding, bowls, and toys — will help protect the dogs in your home.
Dog flu has been diagnosed at all times of the year, not thought to be seasonal like human flu viruses, so taking preventative measures tends to be the best approach. Dog owners who place their dogs in boarding facilities and kennels, even for short periods of time, should ask well in advance whether these facilities have had any confirmed cases recently. If possible, take a tour of any such facility to see that they are well-ventilated, kept clean, and that dogs are not kept in too close proximity to each other.
Since dog flu is not seasonal like human flu viruses, the simplest thing dog owners can do is make sure their dogs keep a discreet distance from sick dogs in public. It is always wise to ask other owners whether their dog has, or has recently had, a cough before allowing dogs to approach each other. In multi-dog households, a dog suffering from canine influenza should also be given separate food and water bowls to minimize the risk of spreading the infection.
Your vet will know best whether the canine influenza vaccine is necessary, or even practical, for the dogs in your home. At present, most single-dog homes whose dogs have limited or occasional contact with a number of other dogs have little to fear from dog flu. Dog owners, on the other hand, should get a flu shot on a yearly basis. After all, how can you take care of a dog who does get sick if you’re laid up in bed with a flu virus of your own?
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