With coronavirus infections in people taking center-stage in recent news coverage and posing a major risk to human populations, it seems a good time to take a look at a feline coronavirus infection. The virus we are talking about is the feline enteric coronavirus (FECV) and its mutation, the feline infectious peritonitis virus (FIPV).
Now, before anybody panics, there is no evidence to suggest that this feline coronavirus, in its enteric form or its mutated FIPV form, is transmissible to people or is in any way responsible for any of the deaths or illnesses reported in the human population. Unfortunately, though, the virus is responsible for a deadly disease in cats known as feline infectious peritonitis, or FIP.
What is FIP?
FIP is a particularly nasty disease seen primarily in young cats. The disease is almost always lethal for affected cats. FIP is considered an incurable disease currently.
There are two forms of the disease recognized.
- The “wet” or effusive form of FIP causes fluid accumulation in the abdominal cavity and/or in the chest cavity.
- The “dry” or non-effusive form causes an inflammatory response known as a granuloma in organ tissues. Most commonly affected are the eyes and central nervous system but any organ can develop these lesions.
Symptoms of the effusive form of FIP include a bloated abdomen, lack of appetite, breathing difficulties, fever, weight loss, diarrhea, and/or jaundice (yellow coloration of the gums and skin).
Symptoms of the non-effusive form depend on where the lesions occur but may include lack of appetite, fever, jaundice, diarrhea, and weight loss as well as ocular and neurologic symptoms.
What do we know about how FIP occurs?
We know that all cats that develop FIP are infected with the feline enteric coronavirus. However, not all cats infected with the feline enteric coronavirus develop FIP. In its most common form, the feline enteric coronavirus is fairly innoculous, usually causing nothing more than a transient case of mild diarrhea if it causes any disease at all.
In some cases, however, the feline enteric coronavirus mutates into the more virulent feline infectious peritonitis virus. We do not fully understand why this happens in some cats and not in others. However, it is believed that there may be a genetic predisposition in some breeds.
In addition to the viral mutation, the immune system of the cat also plays a role in the development of disease. Some cats are able to mount an effective and complete immune response. In these cases, the cat does not become ill. Some cats, however, can only mount a partial immune response. These cats go on to develop the non-effusive form of FIP. Cats that develop the effusive form of the disease are unable to mount any immune response at all.
Is there any hope for cats with FIP?
A drug known as polyprenyl immunostimulant (PI) is offering some hope for cats with the non-effusive form of FIP. Though not effective in all cases, this drug has improved the survival time for some cats treated with the drug..