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December 8, 2022 — Just like humans, cats are affected by and can get sick from many different viruses. Although the COVID-19 pandemic has brought coronaviruses to the forefront, several other types of viruses impact people and cats every day. Pet parents need the latest information to keep their kittens and cats healthy and living their best (nine) lives!

Feline Coronaviruses
Veterinarians have recognized feline coronaviruses for decades. In most infected cats, these viruses cause signs of intestinal disease. In some cats, however, for reasons not entirely clear, the virus mutates and causes feline infectious peritonitis (FIP).

For more than a decade, Morris Animal Foundation has been a leading funder of FIP research. And, while the disease still is almost uniformly fatal, results from studies on diagnosis, treatment and preventive strategies are promising.

Foundation-funded work on feline coronaviruses also helped provide important information to human health researchers in the early days of the COVID-19 pandemic.

Feline Respiratory Viruses
One family of viruses is responsible for most viral infections seen in cats – respiratory viruses. These viruses are everywhere and most cats get their first exposures as kittens, likely from their mothers.

Vaccination helps control symptoms but, unlike for other viruses, it doesn’t prevent infection. In addition, feline herpesvirus-1 (FHV-1), an important cause of respiratory infections in cats, behaves like other herpesviruses – it may go dormant, but can cause flare ups of disease (similar to cold sores in people).

The Foundation has made a significant investment in learning more about this important group of viruses. Our researchers made important discoveries about how to minimize transmission of respiratory infections in shelter cats, the relationship between the feline microbiome and respiratory disease and so much more.

Feline Leukemia Virus (FeLV)
FeLV is a member of the retrovirus family, a group of viruses that includes human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV).

 Signs of infection vary between individuals and outcomes differ depending on the strain of virus, mode of transmission and other factors such as age at infection, stress and the presence of other infections.

The Foundation was an early supporter of studies focused on understanding FeLV and our funding contributed to the development of the first vaccine. Since the introduction of an effective vaccine in 1985, along with widely available screening tests, the incidence of FeLV-related diseases diagnosed in cats has plummeted.

Feline Immunodeficiency Virus (FIV)
When FIV was first described in 1986, the global HIV/AIDS crisis was raging. Many of the features of FIV were similar to HIV (human immunodeficiency virus), and cats became a model for the disease. The virus is transmitted via saliva, with most cats infected through bite wounds.

Just as in people with HIV, some cats can harbor FIV for their entire lives with no signs of illness. Similarly, many cats succumb to other diseases due to the immunosuppression caused by the virus. It’s important to know if your cat has FIV, but if it is asymptomatic no specific treatment is required other than management steps to decrease risk of transmission to other cats.

Although it’s easy to forget about rabies given the number of cats that spend their lives indoors, rabies remains a major health threat in many parts of the world. Many people are surprised to learn that more cats than dogs are diagnosed with rabies in the United States. In some areas, rabies vaccination is required by law so it’s important cat owners are up to date on local vaccination schedules. Talk to your veterinarian about the best vaccination plan for your cat.

Feline Panleukopenia Virus (FPV)
FPV is a virus that tends to slip under the radar when it comes to viral diseases in cats. FPV is a parvovirus – the disease in cats looks a lot like the more familiar canine parvovirus infections seen in dogs. FPV tends to be more common in young cats and kittens.

While FPV was once common and often deadly, vaccination has largely kept it under control until a decade ago, when many areas of the world saw a sudden uptick in infections. Making sure your pet is current on their vaccinations remains the best way to keep this serious illness away.

Tips for Cat Owners
Although many viruses cause illness in cats – circulating in the environment and between cats – the good news is owners can take steps to minimize risks of infection.

First, discuss your cat’s risks for potential virus exposure with your veterinarian. Does your cat go outside at all? Do you foster kittens? Are you thinking of adopting an adult cat? Is your cat immunocompromised? These are just some of the questions that might dictate what testing and vaccination schedule is right for your feline friend.

Second, it’s important to watch your cat closely for any signs of illness, especially if they’ve come in contact with an unfamiliar cat. Even brief encounters can lead to infection.

Third, it’s always a good idea to keep track of your cat’s vaccination and testing history. If you travel with your pet, move locations or switch veterinary clinics, have an accessible copy of your cat’s health history. It will make your cat’s care easier and save you from having to track down important information when you need it the most.

Additional Resources
Latest vaccination recommendations for cats as developed by the American Association of Feline Practitioners (AAFP)
Fresh Scoop podcast on feline viruses including COVID-19
2020 AAFP feline retrovirus management guidelines
An extensive review of feline infectious peritonitis by Dr. Nils Pedersen, world-renowned expert on the disease