Keeping your furry pal happy and healthy is your priority, and doing so includes protecting them from common viral threats. Feline viral infections range from mild to severe and, in some cases, can be lifelong or life-threatening. Read our Just Cats Clinic team’s comprehensive guide to learn about the top feline viral diseases.

Feline herpesvirus

Feline herpesvirus (FHV-1) or feline viral rhinotracheitis, is a common viral infection that infects up to 97% of all cats. Of those cats, 80% develop lifelong infections, which means the herpesvirus can periodically reactivate. The disease is usually mild, causing upper respiratory signs and eye problems, including sneezing, nasal discharge, and conjunctivitis.

Most cats are vaccinated against FHV-1 as part of the combination feline viral rhinotracheitis, calicivirus, and panleukopenia (FVRCP) vaccine routinely given to kittens and adults. However, vaccination doesn’t provide complete protection. Treatments are supportive and may include antibiotics to prevent secondary infections. You can prevent or limit flare-ups by minimizing your cat’s stress level.

Feline calicivirus

Feline calicivirus (FCV) is another respiratory virus that can affect cats of any age but usually infects young kittens. Cats housed in crowded environments, such as shelters or catteries, have a high infection risk. The virus causes respiratory signs and may also cause oral ulcers, fever, lethargy, eye discharge, or joint inflammation.

Most cats are vaccinated against FCV when they receive the FHV-1 vaccine but may be exposed to the virus before the vaccine takes effect. Treatments are supportive, including fluids to address fever, antibiotics to prevent a secondary bacterial infection, and pain relief for oral ulcerations.

Feline immunodeficiency virus

Feline immunodeficiency virus (FIV) is similar to human immunodeficiency virus (HIV), which leads to acquired immunodeficiency syndrome (AIDS). A similar condition can develop in FIV-infected cats, causing immune system dysfunction and exposing them to opportunistic infections. FIV is spread through bite wounds and is often found in outdoor, intact males, although any cat can be infected. The infection is lifelong, with some infected cats living an average lifespan, but others quickly succumbing to the disease.

FIV signs vary, and many infected cats appear healthy until a secondary infection develops. Signs include enlarged lymph nodes, fever, blood disorders, weight loss, recurrent or treatment-resistant infections, eye inflammation, seizures, and oral inflammation (i.e., stomatitis). You can prevent your cat from contracting an FIV infection by keeping them indoors and testing a cat you intend to adopt before bringing them home. You should address your infected cat’s FIV problems as they arise through regular veterinary care and close monitoring.

Feline leukemia virus

Feline leukemia virus (FeLV) is similar to FIV in that a cat has a lifelong infection that weakens their immune system. FeLV tends to cause more severe illness than FIV and puts cats at a significantly increased cancer risk. The virus spreads through close contact among cats, including mutual grooming or shared litter boxes. In addition, an infected mother cat can transmit FeLV to her kittens. Some infected cats experience no FeLV infection signs, but many have a shortened lifespan. FeLV may cause fever, lymph node enlargement, diarrhea, eye disorders, weight loss, neurologic disease, or mouth inflammation—similar to FIV.

FeLV vaccination is highly effective and recommended for all kittens, as the disease is more severe and likely to shorten their life if they are infected at a young age. Before vaccinating your cat, we test them to determine if infection is already present. When your kitten reaches adulthood, we can reassess their lifestyle to determine if continued vaccination is required.

Feline coronavirus

Feline coronavirus (FCoV) primarily affects the intestines, causing mild to moderate gastrointestinal (GI) signs that resolve quickly in most cases. Although rare, some cats infected with FCoV develop feline infectious peritonitis (FIP), a severe and often fatal disease. FIP signs include fever, weight loss, neurologic symptoms, fluid buildup in the abdomen or chest, general malaise, and eye inflammation.

Good hygiene and stress reduction help prevent this virus’ spread throughout multi-cat households. FIP is often deadly and until recently, was not treatable. However, lifesaving treatment is available.

By understanding common feline viral diseases, you can take proactive steps to protect your cat’s health. Keeping your cat’s vaccines up to date and ensuring your feline friend receives regular veterinary checkups with our Just Cats Clinic team help prevent feline viral infections. In addition, when you maintain a clean, stress-free environment, you help minimize your cat’s virus flare-ups. Contact us if you suspect your cat has a viral infection or to schedule your furry pal’s routine preventive exam.