Coronavirus is most often found in young cats or multi-cat households where it is spread through feces and airborne contaminants. Fatalities most often occur in cats who are young or have a weakened immune system.

Coronavirus in cats, or feline infectious peritonitis, is a viral disease caused by certain strains of feline coronavirus. Though most strains of feline coronavirus do not cause the disease to occur, some strains can cause symptoms that range from mild to severe. These strains may also mutate in the cat's body, becoming feline infectious peritonitis virus. This virus attacks the immune system and vital organs, resulting in the death of the cat.

Symptoms of feline infectious peritonitis depend on the type of strain of coronavirus that the cat has contracted, the age of the cat, the cat's immune system and what specific organs are attacked by the virus. The virus can be one of two types, wet or dry, with symptoms depending on the type of feline infectious peritonitis the cat has contracted.

Feline coronavirus is fairly common among cats and is transmitted through the feces of other infected cats or from breathing in contaminants. Feline infectious peritonitis is caused by the feces or airborne contaminants of certain strains of the coronavirus. Some types of feline coronaviruses can mutate and attack the white blood cells, which then carry the disease throughout the body. When this mutation occurs, it causes feline infectious peritonitis.

Feline infectious peritonitis is difficult to diagnose as there is no definitive test that can determine if a cat has a mild form of coronavirus or feline infectious peritonitis. The symptoms can also mimic other diseases or viruses, making it more difficult for veterinarians to diagnose properly.

The veterinarian will ask for the cat's health history, which includes the cat's symptoms, when symptoms first began, and if the cat lives with other cats at home or was frequently placed in a kennel. The veterinarian will examine the cat, listening to the cat's breathing and looking for a distended abdomen. 

Labs, which include a complete blood count and an ELISA (enzyme-linked immunosorbent assay) test, will need to be done. The complete blood count will look for white blood cells that are indicative of an infection while an ELISA test will show the presence of any coronavirus antibodies. A sample of fluid may be taken from the thorax or abdomen for further testing. Additionally, a fecal test using a stool sample may also be performed to detect the virus. Because these tests only show if the coronavirus is present and not if it's mutated, however, the veterinarian will diagnose the cat with feline infectious peritonitis if it doesn't have the symptoms of other viruses or diseases.

Most strains of coronavirus don't require treatment as the cat's immune system will produce antibodies against the virus. Unfortunately, there is no cure if the cat has developed feline infectious peritonitis. Care is centered on keeping the cat comfortable and prolonging its life for a few months. 

If the cat is diagnosed with the non-effusive type of feline infectious peritonitis, medications will be prescribed. Antibiotics will help kill bacteria, immunosuppressants will prevent the virus from mutating, and anti-inflammatory medications will reduce the pain the cat is experiencing and reduce inflammation throughout the body.

Feline infectious peritonitis is fatal in approximately 95 percent of cases. In some cases, the prescribed medications can keep the infection dormant, or in remission, for several months. It's important to follow up with the veterinarian so medications can be evaluated for effectiveness and changed, if needed, in order to allow the cat to be comfortable.

Though there is a vaccine available to prevent feline infectious peritonitis, its use is not recommended by the American Association of Feline Practitioners as it hasn't proven effective in preventing the virus in all cases. 

The best way to keep coronavirus from spreading to other cats is to vigilantly clean the cat's food and water dishes, regularly disinfect the cat's living space and keep sick cats away from other cats in multi-cat households. Kittens should be kept away from other cats, other than the mother, to prevent them from contracting the virus. If a cat passed away from FIP, it is sensible to wait awhile before rehoming a new cat and to thoroughly clean the home.