Feline Viruses

"Feline viruses take many forms including calicivirus, corona virus, leukemia,panleukopemia, and rhinotracheitis. Most viruses cannot be cured since they spread from cell to cell in your cat's body, making it difficult to treat. Because of this treatment is focused on the symptoms while your cat's immune system fights the virus. It has been confirmed that humans can spread the Swine flu H1N1 virus to cats."

There are a number of cat viruses all owners should know about. You can have your cat vaccinated against many of these feline viruses. Talk with your vet about which vaccines your cat needs.

Feline Calici Virus (FCV)

Feline Calici virus is an upper respiratory cat virus that produces flu-like symptoms in cats. It’s usually spread through contact with saliva or eye and nasal discharge of infected cats. Sometimes it is spread through contact with feces.

Symptoms include lack of appetite, discharge from the eyes and nose, fever, and stiff and painful joints and muscles. Difficulty breathing may occur and cats may develop pneumonia. Calicivirus can resemble feline rhinotracheitis, but the main symptom that differentiates the two is sores in the mouth, on the lips or tongue, or on the tip of the nose. Some strains of feline calici ivirus also cause sores on the feet.

Usually supportive care is all that’s needed to treat calcivirus. Antibiotics may be required if secondary bacterial infections set in. Pain medication may also be needed for joint pain.

There is a vaccine for calcivirus. Cats should be vaccinated as kittens and receive annual booster shots.

Feline Corona Virus (FCV)

Feline corona virus is a virus that causes a serious medical condition called feline infectious peritonitis (FIP). It does not cause FIP in all cats, and no one knows why it causes it in some cats but not in others.

Cats exposed to feline corona virus often show no symptoms at all. Others have mild respiratory symptoms. Once they get the virus, they carry it forever, and can pass it to other cats through their saliva or feces.

Like other feline viruses, there is no cure or treatment for feline corona virus. There is also no vaccine.

Feline Infectious Peritonitis (FIP)

Feline infectious peritonitis is triggered by another one of the feline viruses - coronavirus. It isn't clear why 5% to 10% of cats get FIP, but it is believed that either the virus is caused by an immune response to the coronavirus or the virus itself mutates into FIP. The virus can appear weeks or years after the coronavirus appears and is almost always fatal. There is a new treatment out of Europe using feline interferon omega that has helped to either drive the virus into remission or cure a small number of cats.

Feline Leukemia (FeLV)

Despite the name, feline leukemia is not a form of cancer. It is a feline virus that is similar to the HIV virus in people. It affects the immune system, making cats very vulnerable to infections. It is spread through contact with saliva and nasal secretions of infected cats, and also through contact with urine and feces. It is highly contagious.

In the early stages of the disease, there may be few symptoms. In the later stages, there may be many symptoms, including loss of appetite, weight loss, diarrhea, enlarged lymph nodes, and fever. Cats may have multiple infections, such as skin infections, bladder infections, and upper respiratory infections. Seizures may occur.

There is no cure for feline leukemia. Cats usually live about two years from the time of diagnosis.

Your cat should be vaccinated for feline leukemia as a kitten and should receive annual booster shots.

Feline Panleukopenia (FPV)

Feline panleukopenia is also known as feline distemper. It is transmitted through contact with urine or feces of an infected cat. Mother cats can also spread the disease to their kittens

Older cats may not show many symptoms but kittens can become severely ill. Symptoms include severe vomiting and severe, bloody diarrhea. Seizures may also occur. Symptoms usually come on very suddenly.

There is no cure for panleukopenia, and it is often fatal. Treatment involves supportive care, which includes subcutaneous fluids, medication for vomiting and diarrhea, and medication for seizures.

Cats should be vaccinated for panleukopenia as kittens and yearly thereafter.

Rhinotracheitis (Feline Herpesvirus Infection)

Rhinotracheitis is a virus of the upper respiratory system. It’s spread by contact with secretions from an infected cat’s mouth, nose, or eyes. Symptoms are similar to calcivirus but are usually less severe.

Medical treatment is usually not required. Symptoms generally go away on their own within a week. Sometimes secondary infections set in and antibiotics are required.

Symptoms include loss of appetite, coughing (a cat coughing sounds a lot like a cat trying to bring up a hairball), sneezing, runny nose and eyes, and fever.

There is a vaccine for rhinotracheitis. Some cats will get the virus even if they have been vaccinated, but we still recommend you vaccinate your cat.

Cat Avian Influenza

Cat avian influenza is a rare virus. Like it's name implies it is caught when your cat bites into an infected bird. Symptoms are common to many viruses including weakness, fever, and redness in the eyes (conjunctivitis).


Feline Immunodeficiency Virus (FIV)

This virus is transmitted through a cat bite. The problem with feline immunodeficiency virus is that your cat can be asymptomatic for years (without symptoms) and then the virus gradually weakens the immune system.

Cat Swine Flu Virus (H1N1)

The first case of cat swine flu has been confirmed by the U.S. Department of Agriculture. The cat was 13 years old and is the first time the disease has been confirmed in a cat.  For the first time the disease has been passed from a human to a pet.  This was confirmed as a new addition to the list of feline viruses by the University of Iowa.

Symptoms of Cat Swine Flu include lethargy, difficulty breathing and loss of appetite.  To prevent the spread of swine flu to your dog or cat, it is suggested that the same approach used it protect humans is used to protect cats.  This includes humans in the household getting the H1N1 vaccine, frequent hand washing and coughing or sneezing into the bend of the arm.

References for Feline Viruses:


Cornell University College of Veterinary Medicine 

Iowa Department of Public Health


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