Humans aren’t the only ones to catch the flu. Unfortunately, our cats have a set of “flu” illnesses all their own. Most are illnesses that only affect cats, but some are zoonotic (spread from species to species and even to humans). Awareness of these flu bugs can help to get sick kitties the help they need sooner.

The Flu in Cats

Flu in cats - black and white cat

Photo Credit: Heather Dowd

Illnesses that are classified as the flu in cats are not always caused by a strain of the influenza virus. Flu in cats takes the form of an upper respiratory infection. Symptoms that are common to all 5 of the illness listed below include:

  • Fever
  • Runny eyes
  • Runny nose
  • Lack of appetite
  • Lethargy

The flu can be a serious illness for cats – especially young kittens. Secondary bacterial infections are very common with these flus. If you think your cat may have any form of the flu, contact your veterinarian right away.

Vaccines exist for numbers 1, 2,  and 5 below. Always do your research and speak with your veterinarian about the pros and cons of each vaccine before assuming that it is right for your cat. The best ways to prevent the spread of illness are to keep sick cats isolated (with their own food, water, litter box, and toys) and to encourage good hygiene among the humans in the household. Always wash your hands after touching a sick kitty!

#1: Calcivirus

The Calcivirus is one of the most common causes of flu symptoms in cats. This virus has a lot of different forms, much like the seasonal flu that hits humans every year. Cats may develop ulcers in their mouth, pharyngitis (sore throat),  a cough, and inflammation of the trachea.  Some even develop a limp from a transient arthritis (most often seen in young kittens).

A veterinarian can test for the calcivirus by taking a swab from the cat’s throat. There isn’t a specific treatment for this virus, so the symptoms will be treated. A cat can be a carrier of the calcivirus for up to 2 years following the infection.

#2: Feline Herpes

Most cases of the flu in cats are caused either by the calcivirus or feline herpes. The symptoms of feline herpes tend to be more severe than the calcivirus. Frequently cats with feline herpes will experience conjunctivitis (an eye infection) and develop ulcers on their corneas. One a cat contracts the feline herpes virus, the cat remains a carrier (and thus able to spread the disease) for life.

Diagnosing feline herpes is not always an easy task. While there is only one strain of this virus, the cat will only shed it intermittently through  saliva, nasal secretions, and tears. This means that a swab may return a false negative. There is no specific treatment for feline herpes. The symptoms are individually addressed with treatment.

#3: Avian Flu H5N1
Flu in cats - Feel better soon

Photo Credit: Lizbeth*King via flickr

The Avian flu is caused by a type A influenza virus. There are many strains of avian flu, but the one referred to here is named H5N1. This flu made the news in 2006 when it spread from animals to humans. H5N1 is most commonly contracted by birds, but not all infected birds show symptoms of the disease.

Typically cats are resistant to type A influenza viruses, but H5N1 proved to be different. It was found that not only could cats fall ill with H5N1, but they could also spread it to other cats.It is thought that cats mostly become infected with the virus through eating birds which were infected. The cats were found to shed the virus through feces, urine, and nasal secretions. There is no evidence that cats can spread H5N1 to humans.

#4: Swine Flu H1N1

The swine flu is caused by an influenza virus called H1N1. This virus also made the news in 2009 for its ability to spread from animals to humans. Symptoms of H1N1 in cats can range from very mild to severe. Some cats will remain asymptomatic after contracting the virus. In addition to the general symptoms listed above, cats may also have coughing and labored breathing.

A unique characteristic of the H1N1 flu virus is it’s ability to be spread from humans to cats. It is likely that if a cat falls ill after a human has fallen ill with H1N1, that the cat has contracted H1N1. A veterinarian can make a definitive diagnosis by analyzing a throat swab.

#5: Bordetella Bronchiseptica

Bordetella bronchiseptica is a bacteria that causes flu-like symptoms in cats. This is the same bacteria that causes kennel cough in dogs and is related to the bacteria that causes Whooping Cough in humans. Along with the other flu symptoms listed above, bordetella bronchiseptica can cause crackling lung sounds in cats.

A swab of the cat’s throat can detect bordetella bronchiseptica. Antibiotics can be used to treat this flu. Other supportive treatments may be used as well. A cat with an uncomplicated case of bordetella bronchiseptica may recover from the illness within 2 weeks. It is possible for a cat to spread this flu for up to 19 weeks after becoming infected.

Do you have any advice for someone caring for a kitty with the “flu”?