In light of the recent outbreak of CoVid-19 in humans, I want to talk about the feline version of the CoronaVirus.
There are several feline CoronaViruses (FCoV) but they vary widely in their virulence (severity) and clinical signs. FCoV of low virulence usually attack the intestinal cells causing diarrhea and they are usually self limiting, meaning they will subside without medical treatment. More virulent, invasive strains of FCoV produce the disease Feline Infectious Peritonitis (FIP) and these virulent isolates are known as Feline Infectious Peritonitis Viruses (FIPV).
FCoV occurs in both ferral and domestic cats. It tends to infect younger cats (6 to 12 months of age) and older cats (13 years and older), due to a decline in immunity.
The virus is usuallytransmitted by acutely-infected cats through the fecal-oral, oral-oral, or oral-nasal route. However, because FCoV is relatively stable in the environment, under perfect environmental conditions cats can also become infected through environmental contamination, sometimes for up to several months.
Fortunately, FCoV is readily destroyed by most common disinfectants and detergents. Thorough cleaning will significantly reduce the concentration of FCoV in the environment.
Recent studies of cat populations with endemic coronavirus infection (eg, catteries) show that cat population densityis the major risk factor for the deadly strain of coronavirus that causes FIP. Specifically, the outbreak and spread of FIP is increased by
1.) the presence and magnitude of coronavirus-shedding cats in the population, and
2.) the concentration of more FIP-susceptible lines of cats in the population.
The more dense the population, the more chance of FIP spreading because the virus is in greater concentration.
FIP usually comes in two forms. A dry form that creates inflammation and lesions on major organs in the thoracic and abdominal cavities and a wet form that creates high protein fluid build up in those same two cavities. Clinical signs for FIP include a high fever, lethargy, anorexia, and weight loss.
Diagnosing FIP is not that simple. Running a titer for FIP (checking out the FCoV antibody level of the cat) can be misleading. A high titer could mean the cat was exposed in the past but is not currently sick. In addition, a high titer only means that the cat is positive for FCoV but it does not tell us which specific type of coronavirus – it could be FIP or it could be a less virulent strain. To help with the diagnosis a veterinarian will also look at clinical signs and whether or not the cat is responding to treatment. Unfortunately there are other diseases that mimic FIP symptoms such as cancer, systemic fungal diseases, inflammatory bowel disease, and toxoplasmosis.
If you suspect your cat has FIP, it is best to have your veterinarian examine your cat and put all the pieces of the puzzle together to make the diagnosis.
In the past there has not been an effective treatment for FIP, but today there are some novel drugs that are showing some promise. Some of these drugs that could work cannot be tolerated in high doses in cats, so they must be used with caution. There is not a vaccine that works well to prevent FCoV so keeping your cat indoors is the best solution to prevention.