Feline Infectious Peritonitis (FIP) in Cats

Feline Infectious Peritonitis (FIP) in Cats: Understanding and Battling the Disease

Receiving the heart-wrenching news that your cherished feline companion has fallen victim to Feline Infectious Peritonitis (FIP) can be a devastating blow. While recent strides have been made in FIP treatment, it remains a predominantly fatal condition. However, there is a glimmer of hope on the horizon, with a new treatment approved in the United Kingdom in 2021 currently undergoing trials in the United States. Even though the road to recovery can be long and challenging for cat parents and their beloved felines, there is now a beacon of hope shining through the darkness.

What is FIP?

FIP, which stands for feline infectious peritonitis, is triggered by a feline coronavirus. Surprisingly, this coronavirus is relatively common among cats, and most cats have encountered it at some point in their lives. In most cases, cats experience mild diarrhea or remain asymptomatic after exposure. However, in a small fraction of instances, the coronavirus mutates into a more virulent strain, spreading throughout the cat's body and triggering significant inflammation.

It's important to note that while this feline coronavirus belongs to the same family as the COVID-19 coronavirus, these viruses cause entirely distinct diseases and affect different species. In essence, while cats can contract COVID-19 in specific situations, it's not the same as the cat coronavirus responsible for FIP. The feline coronavirus infects both domestic and wild cats, but FIP itself is not transmissible to humans or other animals. In fact, while the coronavirus is indeed contagious, FIP, caused by a mutated form of the virus, does not spread among cats in the typical sense.

People Also Read-Cat Vomiting and Diarrhea

Understanding FIP Risk Factors

The feline coronavirus that can lead to FIP resides in a cat's intestinal system and is primarily transmitted through contact with feces. Cats that share litter boxes face an elevated risk of infection. Less frequently, FIP can also be transmitted through saliva, sneezing, sharing food bowls, or mutual grooming.

Certain factors increase a cat's susceptibility to feline infectious peritonitis, including age, a compromised immune system, or underlying chronic illnesses. While both indoor and outdoor cats of any age can fall victim to FIP, it's more commonly observed in cats aged 6 months to 2 years and certain purebred breeds.

Symptoms of Feline Infectious Peritonitis

As the cat's immune system responds to the virus, inflammation can affect virtually any organ system, resulting in a wide range of symptoms. These symptoms can vary from nonspecific signs like lethargy and loss of appetite to more severe manifestations such as seizures, blindness, breathing difficulties, and more.

Traditionally, there are two forms of the disease: wet FIP and dry FIP. However, infected cats often exhibit symptoms of both forms. Early signs may include appetite loss, fluctuating fever, while advanced symptoms depend on which organs are affected, including fluid buildup in the abdomen or chest, weight loss, vomiting, diarrhea, and more.

Diagnosing FIP

Diagnosing FIP is a complex endeavor as there is no single test exclusively designed for it. Instead, a combination of diagnostic methods, along with a thorough history and physical examination, is used to reach a conclusion.

For cats with the effusive (wet) form of FIP, diagnosis is relatively straightforward, involving testing abdominal or chest fluid for elevated protein levels, a characteristic of FIP.

For those with the non-effusive (dry) form, diagnosis is more challenging due to vague symptoms that can mimic other diseases. A battery of tests may be conducted to rule out alternative causes, including routine bloodwork, brain MRIs, cerebrospinal fluid samples, tissue biopsies, or virus detection in inflamed areas. However, veterinarians may exercise caution when considering tests that require anesthesia, as severely ill cats, whether from FIP or other conditions, face increased anesthesia-related risks.

FIP Treatment: Current and Emerging Approaches

At present, the United States only approves traditional treatments aimed at mitigating the immune response to FIP and managing clinical signs. Unfortunately, FIP continues to carry a grim long-term prognosis for survival. Nevertheless, there is renewed hope on the horizon, with more effective treatments currently undergoing clinical trials.

Traditional FIP treatment focuses on symptom relief, offering palliative care but no cure. Supportive measures, such as appetite stimulants, antibiotics to combat secondary infections, and fluid drainage to alleviate breathing difficulties, are employed. When initiated early, these treatments may extend a cat's life by a few months, particularly if the cat is still in relatively good condition.

In recent years, FIP treatment has seen remarkable advancements. Certain antiviral medications, namely GS-441524 (oral tablets) and remdesivir (IV or subcutaneous injection), have demonstrated the potential to cure FIP through extended dosing regimens. Veterinarians in the United Kingdom and Australia have been prescribing these medications since 2021, achieving long-term remission in over 85% of treated cats—a remarkable turnaround for a previously almost uniformly fatal disease. While clinical trials are ongoing in the United States, stories like Lily, a Bengal cat, and Gridley, a kitten, in remission after undergoing treatment at UC Davis veterinary hospital, offer hope for the future.

Preventing FIP: What Can You Do?

Although there is a vaccine for FIP, the American Association of Feline Practitioners does not recommend its use. This vaccine can only be administered starting at 16 weeks of age, by which time most cats have likely already encountered the virus.

In the absence of a vaccine, proactive measures can be taken to prevent FIP. These include maintaining hygienic litter boxes, preventing overcrowding of cats, and ensuring cats are stress-free and healthy. Stress reduction is particularly crucial as it can weaken the immune system, making cats more susceptible to FIP.

In Conclusion

Feline Infectious Peritonitis is a devastating disease that can develop from what typically begins as a benign coronavirus infection. To safeguard your feline companions, prioritize their health, happiness, and cleanliness in their living environment. If your beloved cat does contract FIP and you reside in the United States, consult your veterinarian about participating in clinical trials for the antiviral treatments that have already shown promise in the United Kingdom and Australia. Hope shines for a brighter future in the battle against FIP.