Humans, dogs, cats, birds, ducks, horses, whales, and seals can all get sick from the flu. If an adult cat comes down with the flu, it's usually not serious. But kittens and felines with chronic health issues, including diabetes, can become sick or even die if they contract the flu. So, if you think your cat has what you would describe as a cold, a visit with your veterinarian would be wise to rule out the flu virus.
How cats catch it
According to the CDC, cited below, "Influenza in cats is thought to spread the same way that human flu spreads: through direct contact (playing or sleeping together, licking, nuzzling); through the air (droplets made from coughing or sneezing, including nasal discharge); and via contaminated surfaces (such as shared food and water bowls, and cage surfaces."
Trudell Animal Health, cited below, notes that while all cats can catch the flu, it occurs more frequently in animal shelters or cat rescues, where many are kept in close quarters. According to Trudell, such cats "can infect one another rapidly through saliva, secretions from noses or through food bowls, toys, sleeping quarters, and by the humans working with them."
According to Trudell, if your cat has the flu virus, he may have a runny nose, watery eyes, and a sore throat. Other symptoms include joint pain, sneezing, fever, and more. Symptoms for cat flu can mimic cat asthma or bronchitis, but your vet can run tests to rule out those issues. In addition, samples can be sent to a laboratory to learn the strain of the virus causing your cat discomfort.
The main goal of treating a cat with the flu is to relieve his symptoms so his immune system can destroy the infection. If a cat is diagnosed with the flu, the CDC advises antibiotics that will quickly make your cat feel better. Vets may also prescribe eye drops or pain medication. Depending on the cat's condition and how well he is eating and drinking, he may need to be hospitalized to receive an extra boost in the form of intravenous fluids.
Preventing infections is challenging but not impossible, Trudell says. If you acquire a new cat, quarantine him from your other cats for two weeks. Also, there are vaccines available that can help protect your cat. Get your vet's opinion about which would be best for your cat.
Quote to remember, "A cat has absolute emotional honesty: human beings, for one reason or another, may hide their feelings, but a cat does not." - Ernest Hemingway
"Influenza in Cats"
Trudell Animal Health
"Feline Upper Respiratory Infection (Cat Flu): What It Is, Signs & Symptoms, And How To Treat It"