Feline infectious peritonitis (FIP) is a serious illness that primarily affects domestic cats, particularly those under two years of age. Although relatively rare, it is a disease that cat owners and veterinarians alike should be aware of due to its potentially fatal outcome. North Vancouver Vet
What Causes FIP?
FIP arises from a viral infection linked to feline coronavirus. There are multiple strains of this virus, varying in their potential to cause illness. Previously, it was thought that only specific strains caused FIP, while others were harmless. However, research now shows that even benign strains of feline coronavirus can mutate into more dangerous forms, triggering FIP in some cats. North Vancouver Vet
This unpredictability makes understanding why certain cats develop the disease while others remain unaffected a challenge. Additionally, there are no definitive laboratory tests to distinguish between the harmless and disease-causing strains of the virus.
How Common Is Feline Coronavirus Compared to FIP?
Feline coronavirus is widespread, with up to 50% of cats in single-cat households and as many as 90% in multi-cat environments becoming infected at some point. Fortunately, most infected cats remain healthy, with fewer than 10% developing FIP. For the general cat population, the incidence of FIP is less than 1%. North Vancouver Vet
Factors That Increase FIP Risk
Certain conditions make cats more susceptible to developing FIP. Cats living in crowded environments, such as shelters or catteries, face higher risks. Stressors like rehoming, surgery, or concurrent infections can also contribute. Genetic predisposition appears to play a role, with purebred cats such as Abyssinians, Bengals, Ragdolls, and Himalayans being more vulnerable. Interestingly, male cats are diagnosed with FIP more often than females. North Vancouver Vet
How Does Feline Coronavirus Spread?
The virus typically spreads through contact with infected feces, often through shared litter boxes. While most cats shed the virus temporarily, a small percentage become lifelong carriers. Although the virus doesn’t survive long in the environment—just 24–36 hours—it can persist longer in colder conditions. Transmission via contaminated objects or clothing is possible within a few hours of exposure. North Vancouver Vet
Recognizing the Signs of FIP
The early symptoms of FIP are often subtle and non-specific. Cats may appear lethargic, lose their appetite, experience weight loss, or develop a fluctuating fever. As the disease progresses, it manifests in one of two forms:
Effusive (Wet) FormThis form leads to fluid buildup in the abdomen or chest, causing a swollen belly or difficulty breathing.
Non-Effusive (Dry) FormIn the dry form, severe inflammation occurs in organs like the eyes, brain, liver, or intestines. Cats with this form often display eye-related symptoms as the primary clinical sign. North Vancouver Vet
Diagnosing FIP
FIP can be difficult to diagnose due to overlapping symptoms with other diseases. Routine blood tests and imaging like X-rays may reveal abnormalities, but they are not definitive. If fluid is present in the chest or abdomen, laboratory analysis can provide valuable insights. However, even fluid analysis might not confirm the disease. In many cases, FIP is diagnosed by excluding other conditions or through biopsy and histological examination. North Vancouver Vet
Treatment Options for FIP
Historically, FIP was considered almost universally fatal. While supportive care with anti-inflammatory drugs like corticosteroids could temporarily improve quality of life, no cure existed until recently. North Vancouver Vet
Newer treatments, such as antiviral drugs like Remdesivir and GS-441524, have shown promising results. These medications are administered over several months and are becoming more accessible in countries like Canada. If treatment is successful, improvement is often noticeable within days. Â North Vancouver Vet
Can FIP Be Prevented?
Vaccines for FIP exist but are not widely recommended due to the unclear effectiveness and complexities of the disease. Discuss with your veterinarian whether vaccination is a suitable option for your cat.
Protecting Other Cats in Your Household
If your cat has been diagnosed with FIP, other cats in your home may have already been exposed to feline coronavirus. However, the likelihood of them developing FIP is low. To minimize risks, wait at least a month before introducing a new cat into the household. In multi-cat environments, thorough cleaning with diluted bleach and maintaining separate litter boxes can help reduce exposure. North Vancouver Vet
Final Thoughts
Feline infectious peritonitis remains a challenging condition for both diagnosis and treatment. While recent advancements in antiviral medications offer hope, working closely with your veterinarian is essential to manage and protect your cat’s health.
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