The five most serious infectious viral diseases in cats are feline viral rhinotracheitis (FVR), feline panleukopenia (i.e., feline distemper), feline leukemia (FeLV), feline immunodeficiency virus (FIV), and feline infectious peritonitis (FIP). Our Animal Internal Medicine and Specialty Services team wants you to know more about these viruses to help you provide the care and protection your cat needs. Read on to learn the infection route, disease course, treatment options, recovery prognosis, and prevention methods for each of these feline viruses.

#1: Feline viral rhinotracheitis (FVR)

FVR is a major cause of upper respiratory infections in cats.

  • Infection route — Respiratory viruses in cats are highly contagious and spread easily among cats who have social contact, share the same caretaker, and eat together. 
  • Disease course — Signs in most cats include runny eyes and nose, sneezing, coughing, decreased appetite, lethargy, hoarseness, or fever for 7 to 10 days. 
  • Treatment options — Adult cats with mild symptoms may require supportive care only, whereas extremely sick kittens may require eye medication, anti-virals, antibiotics, or hospitalization.
  • Recovery prognosis — Most cats recover well, although severe infections can result in permanent eye damage. The virus can remain in the cat’s system and cause intermittent illness episodes.
  • Prevention methods — FVR, which is caused by a herpesvirus, and calicivirus are responsible for 90% of upper respiratory infections in cats. FVR and calicivirus (FVR-C) vaccinations can help prevent infection and lessen disease severity. Indoor cats with the proper environment and who are not overcrowded have a decreased risk.

#2: Feline panleukopenia

This disease of cats is also known as feline distemper.

  • Infection route — This virus infects cats through the mouth or nose, and can survive in the environment for a year.
  • Disease course — The virus moves from the kitten’s throat to the bone marrow and intestines in two to seven days, causing lowered, or absent, white cells, lowered immunity, dehydration, diarrhea, overwhelming infection, and often death.
  • Treatment options Hospitalization and intensive care are required for the best chance for survival.
  • Recovery prognosis Kittens infected before birth can suffer permanent brain damage. Kittens who get better are contagious for six weeks after recovery.
  • Prevention methods Vaccination is highly effective in preventing feline panleukopenia, which is the P in FVRCP or three-in-one vaccine.

#3: Feline leukemia (FeLV)

FeLV mostly causes immunodeficiency, but in 20% of infected cats can cause leukemia or lymphosarcoma.

  • Infection route — Cats contract this retrovirus through grooming, litter pans, food bowls, bite wounds, before birth, and through nursing.
  • Disease course — Cats may develop two cancer forms from this virus—leukemia and lymphoma. Cats will remain infected, although they may not always seem sick or be shedding the virus.
  • Treatment options — Feline leukemia has no cure. Cats with lymphoma respond to treatment more often. 
  • Recovery prognosis — Feline leukemia is responsible for more deaths than any other virus—most cats with persistent, progressive infections die within three years.
  • Prevention methods Disinfectants easily kill the Feline leukemia virus, which lives only for minutes outside the cat’s body. Infection can be prevented by a series of vaccinations as a kitten, followed by a booster in one year, and subsequent boosters based on risk.

#4: Feline Immunodeficiency Virus (FIV)

This virus is analogous to HIV in people and, likewise, causes immunodeficiency. 

  • Infection route  — FIV is transmitted through bite wounds and breeding, not casual contact.
  • Disease course — FIV causes deficiencies in the immune response, making the cat more prone to severe infections. Monitor your cat closely and provide a minimum of twice yearly physical exams.
  • Treatment options — This infection is managed rather than cured. FIV-positive cats need to stay indoors and be prevented from fighting with housemate cats. Never feed them raw food, provide immune support such as antioxidants, and keep up with parasite prevention. 
  • Recovery prognosis — Five years after infection, 20% of cats have died, 20% are alive but sick, and 60% are recovered but sick periodically.
  • Prevention methods — FIV prevention requires that biting, fighting, and breeding be avoided at all times. The FIV vaccine caused problems during testing and is no longer available in the U.S.

#5: Feline infectious peritonitis (FIP)

While most infected cats remain asymptomatic, this disease is highly fatal if clinical signs develop.

  • Infection route — Feline enteric coronavirus is passed among cats when they shed the virus in the litter box. Some cats have an abnormal disease course and develop FIP.
  • Disease course — Cats can develop the FIP wet form, where fluid accumulates in the abdomen or chest, or the dry form, with inflammation but no fluid build-up.
  • Treatment options — FIP treatment is currently unavailable in the U.S. Immunosuppressive medication may slow progression, and fluid removal can make cats more comfortable. 
  • Recovery prognosis — FIP is 100% fatal.
  • Prevention methods — FIP is not contagious, despite starting as a viral infection. A vaccine is available, but does not help in most situations. To decrease the chance of FIP, avoid early weaning, overcrowding, and stress among cats, and always provide one more litter box than the number of cats.

Whether you recently adopted a kitten or have a houseful of cats, this information can help your felines stay healthy, but should you have concerns about your pet, our caring Animal Internal Medicine and Specialty Services team is here for you 24 hours a day, seven days per week. Call us any time, and our specialists will expertly address any questions you may have about infectious viral diseases in your cat or kitten.