Contributed by Sarah Wooten, DVM, CVJ.
Understanding Canine Influenza: Symptoms and Treatments for the Dog Flu
“Can dogs get the flu?” I am often asked this question by clients, and the answer is yes, dogs absolutely can and do get the flu. Canine influenza is just as contagious as the human flu, and it makes dogs just as miserable as it makes humans.
Canine influenza infects dogs of any age. Just like human influenza, the virus that causes dog flu can mutate quickly and make new infectious strains. The two most common strains of canine influenza in the United States are H3N8 and H3N2. H3N8 was first identified in Florida in 2004, and is now present in most, if not all, states. H3N2 was identified in 2015, when it caused an outbreak in Chicago and was most likely transmitted to dogs through a mutation in bird flu. According to the American Veterinary Medical Association (AVMA), cases of canine H3N2 have also been found in Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana and Illinois, and it’s still spreading. There is no evidence at the time of writing that either strain can infect humans.
How Do Dogs Get the Flu?
Canine flu is spread through respiratory secretions from barking, sneezing and coughing. Since the virus can remain active in the environment for up to two days, it can also be spread indirectly. If a dog comes into contact with an item that has been contaminated with respiratory secretions from a dog infected with the flu, then that dog can become infected as well.
Dog Flu Symptoms
Most dogs infected with dog flu develop only mild symptoms. Dogs infected with the flu look just like humans with the flu and can suffer from fever, lethargy, lack of appetite, coughing, sneezing and nasal and/or ocular discharge. The most common sign is a cough that lasts up to three weeks, even with antibiotic treatment.
Canine flu is very contagious: It has a nearly 100 percent infection rate, and about 80 percent of dogs who are exposed to the flu virus will show signs. The remaining 20 percent of dogs who do not get sick will still shed the virus and infect other dogs. That means even if your dog does not experience dog flu symptoms, they are still a carrier of the virus and can spread it to other dogs or environments they come into contact with.
Diagnosing Your Pup With Dog Flu
The signs of canine flu can be confused with other infectious diseases, such as kennel cough, and a diagnosis of the flu cannot be made by your veterinarian without testing. There are a variety of tests available, most of which require a simple swab from the throat or the nose. Veterinarians do not tend to keep these tests in-house. It is likely that the sample will have to be sent to a lab, and test results may take a couple of days.
Treating Dog Flu Symptoms
If your dog is infected, your veterinarian will be your best resource for guidance about treatment. There is no cure for influenza in dogs, and treatment is purely supportive. Your veterinarian may prescribe antibiotics for any secondary bacterial infections (a lot of dogs with the flu will get sinus infections) and anti-inflammatories for fever and malaise. He or she also may recommend ways you can encourage your dog to drink lots of clear fluids. If the dog is dehydrated, your veterinarian may recommend treating him with subcutaneous fluid therapy or, for the more severe cases, intravenous fluid therapy.
Dogs who are infected with canine influenza are very contagious. If your dog has been diagnosed with the flu, the AVMA recommends he be isolated from all other dogs for four weeks. In addition, it is recommended you disinfect the environment with the disinfectant of your choice—canine influenza is easy to kill. Wash and disinfect all bedding, bowls, toys and other items that your dog has been in contact with. If you have multiple dogs, change your clothing before you interact with other dogs to prevent the disease from spreading.
There are yearly influenza vaccines available for dogs for both H3N2 and H3N8. If your dog is in frequent contact with other dogs at the groomer’s, day care, boarding facilities, training facilities or dog parks, or if you travel with your pet, then you may want to consider getting your dog vaccinated against canine influenza. Talk with your veterinarian about your dog’s risk.