Cats enter our lives in various ways—while some feline additions are carefully considered, researched, and interviewed, others simply arrive on our doorstep as if we’d been expecting them all along. No matter who adopted whom, your cat has solidified a place in your home and heart—and you want to ensure they enjoy a long, healthy life. This means protecting them against dangerous viral diseases that can damage their long-term health, or lead to premature death. 

To simplify the alphabet soup of feline infectious diseases, Stack Veterinary Hospital has composed the following guide to the most common transmissible conditions in cats.

#1: Feline retroviruses—feline leukemia and feline immunodeficiency virus

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), which attack the immune system, are transmitted by direct contact with infected cat saliva. FeLV is commonly spread among cats who are housed together and may mutually groom or share food bowls and toys. FIV is transmitted through deep fight wounds, such as scratches and bites, and is diagnosed most commonly in unneutered male cats.

Healthy cats exposed to FeLV can clear the virus without any signs, while others may experience vague short-term signs before the virus goes dormant. Cats with FeLV or FIV can live relatively normal lives for years before the viruses reemerge, damage the immune system, and cause visible illness. Signs for both viruses are similar, and may include:

  • Lethargy
  • Loss of appetite
  • Dull hair coat
  • Weight loss
  • Pale gums, or gum inflammation
  • Fever
  • Diarrhea
  • Eye or nasal discharge

Feline retrovirus prognosis and prevention

In both conditions, cats often succumb to secondary infections—not the virus itself—because of their weakened immune system. Anemia and cancer are common sequelae to feline retroviruses, and the ultimate cause of death for many infected  cats.

Cats who test FeLV- or FIV-positive should be spayed or neutered, and housed indoors. Regular veterinary care, and prompt illness management can help these cats live relatively long lives until the virus reappears. FeLV vaccination is recommended for kittens and young or outdoor cats. No FIV vaccine is available.

#2: Feline infectious peritonitis

Feline infectious peritonitis (FIP) is a mutated version of a common feline coronavirus that normally causes mild gastrointestinal or respiratory signs. However, the mutation, which affects 10 percent of cats, invades the white blood cells, and causes widespread inflammation and organ damage. Although FIP can infect cats of any age, immunocompromised cats (i.e., kittens, unvaccinated, sick, and elderly cats) are most vulnerable.

The feline coronavirus is readily spread through fecal-oral contact, with outbreaks common in shelters and catteries where cats are kept in close quarters. The feline coronavirus is contagious, yet the mutation is not, and why the virus mutates in some infected cats but not others is unknown.

Because FIP can appear weeks, months, or years after initial exposure,  recognizing the following signs is important:

  • Loss of appetite
  • Lethargy
  • Weight loss
  • Depression
  • Fever
  • Respiratory distress
  • Unsteady gait
  • Pot-bellied appearance
  • Seizures

FIP prognosis and prevention in cats 

Sadly, FIP is untreatable. Affected cats are offered supportive care to keep them comfortable and pain-free until signs progress. FIP is best prevented with up-to-date preventive veterinary care, and avoiding contaminated environments.

#3: Feline panleukopenia

Feline panleukopenia is a virulent, potentially lethal parvovirus that primarily affects kittens 3 to 5 months of age. Feline panleukopenia is unrelated to the canine parvovirus, but transmission and pathology are similar—the virus is transmitted by direct contact with bodily secretions (e.g., nasal, fecal, urine), and can live in the environment for up to one year. Feline panleukopenia attacks an infected cat’s intestinal lining, leading to rapid malnutrition and decompensation. Signs commonly include:

  • Depression
  • Loss of appetite
  • Fever
  • Vomiting 
  • Severe diarrhea
  • Lethargy
  • Nasal discharge
  • Dehydration

Feline panleukopenia prognosis and prevention

Kittens less than 8 weeks of age have a poor prognosis, and nearly 90 percent of infected cats die without veterinary intervention. Treatment is supportive, and focused on correcting dehydration, eliminating clinical signs, and restoring nutritional status. Surviving cats acquire a lifelong protective immunity against the virus.

Panleukopenia vaccination is highly effective, with a series beginning at 6 to 8 weeks old. After an initial adult booster at a year old, cats may be revaccinated, based on their lifestyle.

#4: Feline upper respiratory viruses

The most commonly transmitted upper respiratory viruses are feline herpes virus (i.e., feline viral rhinotracheitis [FVR]) and calicivirus. The viruses are transmitted rapidly through respiratory droplets (i.e., sneezing, coughing) among cats kept in close proximity. Identifying infected cats can be challenging, as some carrier cats show no outward signs, while others are visibly ill with signs that include:

  • Eye discharge
  • Conjunctivitis
  • Sneezing
  • Coughing
  • Lethargy
  • Loss of appetite
  • Oral ulcers

Feline respiratory virus prognosis and prevention 

Healthy cats may clear respiratory infections without medical attention, while others require treatment, and may experience periodic flare-ups, especially when they are stressed. Vaccination against feline respiratory diseases (FVRCP) is beneficial, and recommended for cats of all ages. The vaccine does not prevent all infections or transmissions, but significantly lessens the clinical signs. 

Infectious diseases are heartbreaking, and an ever-present threat against cats. Ensure your feline friend is protected, by maintaining their preventive care at Stack Veterinary Hospital. Vaccinations, parasite prevention, high quality nutrition, and conscientious care are the best ways to safeguard your cat, and ensure their immune system is healthy and robust. Schedule an appointment to update your cat’s care, and give them the protection they deserve.