Cats are susceptible to viral infections that can impact their health. Some of these infections clear with or without treatment in a few days or weeks, while others linger in the body and cause lifelong problems. Cats with chronic viral diseases require extra care and attention, because their immune systems are compromised. Our Aberdeen Veterinary Clinic team shares what you need to know about common feline viral diseases.

Feline herpesvirus

Feline herpesvirus (FHV-1) is cats’ main respiratory illness cause, with nearly all cats being exposed during their lifetime. The initial infection causes respiratory signs, including sneezing, conjunctivitis, nasal discharge, and congestion. These clear after a few days, but the virus then moves into local nerve cells where it sits dormant for months or years, only to reactivate if your cat is stressed or ill. Some cats never have recurrences while others struggle with chronic eye ulcers or nasal problems. 

Feline leukemia virus and feline immunodeficiency virus

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) cause lifelong infections and significantly impact an affected cat’s immune function. FeLV and FIV are retroviruses, similar to the human immunodeficiency virus (HIV) in people. These viruses may cause mild illness during the initial infection then quietly lurk in the body and replicate for months or years before they cause immune system problems, potentially leading to secondary infections, uncontrolled inflammation, or cancer. 

Cats with retroviruses can live completely normal lives, but they may suffer from chronic or life-threatening consequences at any time. Somewhere between 2% and 30% of cats are infected by one or both viruses, depending on the population in which a cat lives and their risk factors. We recommend all kittens and new feline household additions be tested for FIV and FeLV, which our team can perform during an office visit and get immediate results. We also recommend testing anytime an outdoor-roaming cat or one living with an infected cat becomes ill.

Feline coronavirus and feline infectious peritonitis

Feline coronavirus (FCV) has been present in the feline population for many decades and is not related to the recent human coronavirus. FCV can infect any cat but most commonly occurs in shelter and rescue facilities, causing mild self-limiting diarrhea or respiratory signs. Despite the infection’s mild initial nature, FCV can mutate in less than 10% of cats and cause feline infectious peritonitis (FIP). Up until recently, FIP was considered a death sentence, however, new treatments are providing pet owners with hope.

Blood testing is possible to detect coronavirus, but cannot predict which few cats will develop FIP. Kittens younger than 18 months are most often affected, with the disease attacking their kidneys, eyes, and neurologic systems, or causing fluid to build up in the abdomen and chest. FIP diagnosis can be presumptively made based on signs combined with characteristic blood abnormalities or fluid analysis.

Treatment and prevention of feline viral diseases

FHV-1, FIV, FeLV, and FCV are chronic diseases with no known cures. No treatments are required during asymptomatic periods, but some cats will require veterinary care to combat specific disease signs during flare-ups. Antimicrobials, anti-inflammatory medications, specialist visits, surgeries, and hospitalizations may be required to address complications, such as eye inflammation, severe mouth inflammation, skin infections, or neurologic disease. FIP treatment is possible with a promising new drug, but the remedy is not yet approved by the Food and Drug Administration (FDA) and can be difficult for you to obtain from a trusted source. However, because no other treatments are effective, some pet owners are willing to accept the risks.

Vaccination is an important strategy for keeping cats healthy. The core feline viral rhinotracheitis, calicivirus, panleukopenia (FVRCP) vaccine contains protection against FHV-1 but typically reduces disease severity rather than preventing infection completely. An FeLV vaccine is available and is recommended for all kittens, but the vaccine is optional for adult cats based on risks. Although available in the past, FIV and FIP vaccines are no longer recommended because of their questionable effectiveness. 

The best way to prevent your cat from contracting a viral disease is to limit their exposure. Therefore, you should keep your feline indoors when possible and neuter or spay your outdoor cat to limit their propensity to roam, breed, or fight. Nearly all cats have been exposed to FHV-1 and FCV, so keeping them isolated is not necessary. However, you should not let cats with known FeLV or FIV infections interact with healthy cats or go outdoors. If infected and uninfected cats have lived together for some time, separating them may not be necessary, but you should avoid bringing new cats into your home.

Managing cats with chronic viral diseases

Cats with viral diseases are more likely to develop infections and cancer than unaffected cats, and their immune systems are more susceptible to stress’s negative effects. Keeping a clean home, including your cats’ bedding and litter boxes, will help reduce infection risks. Provide your cats with plenty of space to roam in the house, a predictable routine, easy access to necessary resources, and protected quiet spaces where they can feel safe. 

Routine veterinary visits are crucial for infected cats, who may become ill at any time. Our veterinary team will pay close attention to your cat’s dental, eye, and neurologic health along with their lymph node size and blood parameters so we can address minor problems before they become severe.

Viral infections are a significant threat to your cat’s health, but many cats with chronic viral diseases can live high-quality lives with proper care. By understanding viral threats and ensuring your cat receives comprehensive veterinary care from our Aberdeen Veterinary Clinic team, you can maximize your feline companion’s health. Schedule your cat’s virus screening test or routine wellness visit, or if you are concerned about their virus status.