Feline Infectious Peritonitis (FIP): A Cat’s Worst Enemy

Updated: August 18, 2023


Curious about Feline Infectious Peritonitis (FIP) and its impact on our cherished feline companions? This enigmatic ailment arises from a potent strain of feline coronavirus, claiming the lives of 95% of afflicted cats. Unraveling the intricacies of FIP, its symptoms, and potential remedies is a quest that beckons our attention.

FIP manifests in two distinct forms: dry and wet. The dry variant elicits indicators like weight loss, listlessness, and fever. Conversely, the wet form mirrors these signals but introduces an additional dimension – the accumulation of fluids in the lungs or abdomen. This divergence proves pivotal, aiding veterinarians in identifying the malady and gauging its severity.

Interestingly, not all feline coronavirus strains are malevolent. Numerous cats harbor harmless iterations, recognized as feline enteric coronavirus. Astonishingly, a breakthrough in 1981 spotlighted a feline coronavirus closely akin to FIP. Yet, unlike its fatal counterpart, this strain prompts only mild diarrhea and swiftly recedes without complications.

Tragically, FIP endures as an indomitable adversary. While a vaccine exists, its applicability remains limited and imprudent for all feline companions. Safeguarding our beloved pals pivots on staying well-informed, discerning the warning signs, and promptly enlisting medical intervention if troubling symptoms arise.

Through unwavering vigilance and cognizance, we aspire to diminish the pernicious influence of this ailment on the lives of our treasured furry confidants.

What Are the Symptoms of FIP?

FIP stands as a perplexing puzzle, as it can lurk within infected cats for weeks, months, or even years without displaying any discernible symptoms. Only a small fraction of these felines ultimately succumb to full-blown FIP, a result of their immune systems responding abnormally.

Let’s delve into the two distinct incarnations of this ailment and their corresponding signs.

Initially, cats exposed to FIP remain asymptomatic, rendering early detection an uphill task. However, FIP unveils itself in two forms: wet and dry. The wet variant advances swiftly, often culminating in death within a fortnight or even sooner from symptom onset.

In contrast, dry FIP is no less fatal, but it progresses more gradually, typically claiming a cat’s life within a span of two years.

Initially, FIP symptoms may manifest mildly, encompassing activities like sneezing, wheezing, fever, lethargy, and diarrhea. Over time, these indicators intensify, and even antibiotics prove futile.

Wet FIP engenders the accumulation of fluid in the cat’s stomach and/or lungs. While the abdomen might appear distended, it generally elicits minimal discomfort. Fluid-swathed lungs precipitate breathing complications, prompting infected cats to sprawl on their sides, laboring to breathe and emitting wheezes in their struggle for air.

Wet FIP often erupts as a sudden crisis, with death trailing close on the heels of the initial symptoms.

On the flip side, dry FIP materializes through lethargy, fever, appetite loss, diarrhea, despondency, and weight reduction. It claims its victims at a more gradual pace, yet there exists no recourse for either iteration of the disease.

Should you suspect that your feline has fallen prey to either variant of FIP, summoning your veterinarian without delay is of paramount importance.

Swift intervention might help alleviate symptoms and furnish your furry companion with optimal care.

How Do Cats Catch Feline Infectious Peritonitis (FIP)?

FIP is contracted by cats through exposure to the saliva or feces of other cats already infected. Surprisingly, even indoor cats can fall victim to FIP. This can occur either due to contact with their infected mother during kittenhood or occasionally through interactions with other indoor cats that remain asymptomatic carriers.

A significant number of cats harbor the virus without succumbing to full-blown feline infectious peritonitis. Intriguingly, there’s no standard test available to detect the virus. Regrettably, this lack of a definitive diagnostic method renders safeguarding your cat from this ailment nearly insurmountable. However, maintaining clean litter boxes and keeping them separate from food sources can be beneficial, particularly in households with multiple cats.

Why Can’t My Cat Be Tested Before FIP Develops?

Diagnosing feline infectious peritonitis (FIP) is far from straightforward, as there exists no straightforward diagnostic test. Identification of FIP hinges on its symptoms, only after eliminating other potential feline ailments. Veterinary professionals ascertain the presence of FIP through a combination of blood tests and biopsies.

Given that FIP often emerges as an acute feline crisis, veterinarians might entertain suspicions of the condition early on. However, no solitary blood test possesses the precision to definitively identify the disease. The challenge lies in the fact that blood tests designed to detect antibodies in a cat’s bloodstream merely reveal exposure to a feline coronavirus. Regrettably, these tests fail to differentiate exposure to the coronavirus causing FIP from other variants. Moreover, even if a cat has been exposed to FIP, it doesn’t inevitably progress to the full-blown disease. Consequently, blood tests hold limited predictive value.

Veterinarians, based on their observation of the cat’s symptoms, can often develop a fairly accurate initial assessment of whether FIP might be at play. Subsequent blood tests that show elevated levels of coronavirus antibodies may further corroborate the diagnosis, albeit solely on that foundation.

Can FIP Be Treated?

While the symptoms of feline infectious peritonitis (FIP) can be managed, it’s important to note that FIP itself remains an incurable disease. Your veterinarian’s approach will primarily focus on easing your cat’s symptoms as they arise, which could involve measures such as draining accumulated fluids and administering blood transfusions. In attempts to alleviate symptoms, corticosteroid drugs, antibiotics, and cytotoxic drugs might be employed. In rare instances, these treatments may lead to temporary remission. However, it’s worth preparing for the possibility of your vet recommending euthanasia, especially if your cat’s condition is severe.

Treatment is more likely for the dry form of the disease, which can extend over a span of up to two years, compared to the wet form that often heralds imminent death. When wet FIP is diagnosed, the cat’s suffering and impending demise are often imminent. It’s advisable to consider these realities before embarking on an intricate regimen of drugs and interventions that may alleviate symptoms but won’t ultimately ensure the cat’s survival.

In the dry form of FIP, internal granulomas or scar tissues develop on various internal organs. Managing the dry form involves pinpointing the affected organs and then addressing pain and other symptoms associated with them.

Researchers persist in their quest for new drugs to treat or potentially cure feline infectious peritonitis. Antiviral drugs and immune response modifiers offer some promise, though as of now, no definitive cure has emerged.

Cure for FIP (Video)

How Common Is FIP?

Feline infectious peritonitis (FIP) is a relatively uncommon occurrence among cats. While cats frequently encounter various strains of coronavirus, very few of them progress to display symptoms of FIP. The primary route through which cats contract the FIP coronavirus is from their mothers before birth. However, only a small fraction of those kittens will eventually mature and develop full-blown FIP.

Instances of FIP are slightly more prevalent in environments where multiple cats coexist, such as shelters and boarding facilities. Vigilant adherence to meticulous cleanliness and prioritizing the health of all cats within the group setting are the most effective preventative measures. Although FIP is undoubtedly a disconcerting and fatal feline ailment, finding comfort in its relative rarity is a worthwhile perspective.

What About Cats That Do Recover?

Exceptions can indeed challenge even the most steadfast rules. In the case of FIP, where 95% of affected cats succumb to the disease, the remaining 5% defy the odds.

It’s important to recognize that while some cats manage to recover from FIP, veterinarians are not attempting to coerce pet owners into euthanasia or downplaying the severity of FIP. Veterinarians are invested in finding a cure for this ailment. Recommendations for euthanasia stem from a desire to spare cats from painful deaths rather than prematurely ending the lives of those with a good chance of survival.

Ultimately, the decision of whether to euthanize a beloved pet rests with the owner. Some individuals opt to fervently care for their cats, exploring every conceivable treatment avenue in the hope of falling within the fortunate 5%. Should this be your chosen path, your veterinarian can offer guidance and likely provide regular check-ups for your cat.

For those with multiple cats and concerns about transmission, be reassured that it’s unlikely for the illness to spread from an infected cat to its companions. Cats displaying active symptoms shed minimal amounts of FIP, and it’s plausible that your other cats are carriers without ever developing symptoms.

While there’s no guaranteed prevention, isolating the sick cat and providing a separate litter box can be a prudent step. If your cat’s health doesn’t improve, at least you’ve made an effort. However, it’s crucial to be aware that the cat’s condition may deteriorate rapidly, particularly with the wet form of FIP.

Why Do Some Cats Get FIP and Not Others?

The enigma of why some cats fall victim to FIP symptoms while others remain untouched is a multifaceted conundrum. Curiously, even within the same litter, all but one kitten might remain healthy. The baffling question persists: why that lone one, and not the rest?

While some contend that stress serves as a trigger, the reality is that no definitive answer exists. Researchers speculate on a dual set of conditions that must align for fatal FIP to manifest: 1) the virus must undergo mutation into the FIP form, and 2) the cat’s immune system must respond with a deficiency that permits rapid virus propagation throughout its system.

If stress were the decisive factor, wouldn’t all kittens from the same litter succumb to feline infectious peritonitis following a turbulent period, such as relocation or the loss of a mother? Attempting to address questions that evade answers often leads to undue guilt being shouldered by pet owners. If your cat suffers from FIP, it’s essential to recognize that it’s not your fault; neither your actions nor inactions could have forestalled its occurrence.

Can My Older Cat Get FIP? Can My Dog Get It? Can I?

The majority of cats that succumb to feline infectious peritonitis are under two years of age. Nonetheless, older cats can also be afflicted, particularly if they surpass fourteen years in age and/or grapple with additional feline immunodeficiency diseases, such as feline leukemia. While primarily affecting young cats, FIP holds the potential to afflict any feline, regardless of age.

It’s worth noting that dogs are impervious to feline infectious peritonitis, and humans are equally immune. This illness exclusively targets cats. Although dogs and humans can harbor coronaviruses, they cannot contract the virus from a cat, even one that is gravely ill.

What About a Vaccine?

An available vaccine for feline infectious peritonitis (FIP) exists, yet its usage sparks controversy. The American Association of Feline Practitioners classifies the FIP vaccination as “not generally recommended.” This doesn’t inherently suggest the vaccine is unsafe or ineffective, but rather that it isn’t a routine requirement for most cats.

Before administering the FIP vaccine, a cat must undergo testing to determine its exposure to feline coronavirus. This process can involve various costly blood tests, with results sometimes proving inconclusive. If it’s deemed beneficial for the cat, the vaccine is administered nasally. If you’re considering vaccinating your cat against FIP, it’s advisable to discuss it with your veterinarian. The incidence of cats contracting this debilitating ailment is quite minimal compared to the global feline population. Consequently, your vet might discourage the FIP vaccine.

If the decision is made to proceed with vaccination, the regimen involves an initial dose for cats at least sixteen weeks old, followed by a second dose three to four weeks later. Subsequent yearly booster shots are recommended once the vaccine is administered.

Putting It All in Perspective

In the wild, the cycle of life is harsh for kittens, with many succumbing to predators, injuries, hunger, or disease before reaching adulthood. Feline infectious peritonitis (FIP) is a natural mechanism that nature employs to eliminate weaker kittens early on.

However, our domesticated pets are sheltered from these harsh realities, and witnessing a young cat fall prey to a devastating illness like FIP can evoke a profound sense of unfairness and sorrow. Our connection with these feline companions brings these tragedies to the forefront of our consciousness.

The impact of FIP is especially poignant since it often strikes cats under two years of age. In many instances, you’ve only just begun to build a bond with your young cat. It’s important to acknowledge that feeling grief during this period is entirely normal. Engaging in conversations with fellow pet owners who’ve faced similar losses can help you realize the validity of your emotions and the possibility of healing. Rest assured, the love and care you provided your cat have undoubtedly enriched its life.

While you might initially feel a reluctance to adopt another cat, this sentiment is frequently fleeting. When the time is right, and another feline captures your attention or destiny introduces a cat into your life, don’t hesitate to welcome it into your home and heart. Most indoor cats enjoy lives spanning ten to sixteen years or more, offering ample companionship.

Loving a cat necessitates a special person with a big heart. Permit yourself to grieve, mend, and embrace a new feline companion when you’re prepared to do so.

FIP: Feline Infectious Peritonitis (Video)

What is Feline Infectious Peritonitis (FIP)?

FIP, short for Feline Infectious Peritonitis, is a perplexing and often fatal disease affecting cats. It’s triggered by a potent strain of feline coronavirus and is responsible for a staggering 95% of diagnosed cats’ deaths.

What are the key symptoms of FIP?

FIP comes in two forms: dry and wet. The dry form showcases symptoms like weight loss, lethargy, and fever. The wet form manifests similar signs but also includes fluid accumulation in the lungs or abdomen, exacerbating the gravity of the condition.

How does FIP differ from other feline coronavirus strains?

Not all feline coronavirus strains are lethal. Many cats carry benign variations known as feline enteric coronavirus. In 1981, a breakthrough highlighted a strain closely resembling FIP, yet causing only mild diarrhea, which resolves without complications.

Is there a cure for FIP?

Regrettably, FIP remains incurable. Although a vaccine exists, it’s not universally recommended and can’t be administered to all cats due to its limited efficacy.

How can I protect my cat from FIP?

Staying informed is the first line of defense. Recognizing symptoms promptly and seeking immediate veterinary care is crucial. Since FIP is challenging to prevent, focus on maintaining your cat’s overall health and well-being.

Can the wet and dry forms of FIP be treated differently?

The distinct forms share common symptoms but differ in fluid accumulation. While treatment approaches might overlap, veterinarians adapt strategies based on the specific manifestation and severity of the disease.

Should I consider the FIP vaccine for my cat?

Consult your veterinarian before considering the vaccine. Due to its limitations and potential risks, not all cats are suitable candidates. Your vet can guide you on the best course of action based on your cat’s individual circumstances.

How does awareness impact FIP’s impact on cats?

Vigilance and knowledge are crucial. By staying informed, recognizing potential symptoms early, and seeking medical care promptly, you can potentially alleviate the disease’s impact and improve the odds of successful management.

Can FIP be transmitted between cats?

Yes, FIP can be transmitted through close contact between cats, particularly in multi-cat environments. However, not all cats exposed to the virus will develop FIP.

What’s the prognosis for cats diagnosed with FIP?

The prognosis for cats with FIP varies widely. The disease’s progression is unpredictable, and the outcome depends on factors like the cat’s age, overall health, and the form and severity of FIP.


Feline Infectious Peritonitis (FIP) stands as a poignant reminder of the intricate relationship between our beloved feline companions and the mysteries of infectious diseases. This enigmatic ailment, propelled by a potent strain of feline coronavirus, has the power to shatter the lives of cats and their caregivers alike.

As we delve into the realm of FIP, it becomes evident that its impact is far-reaching and its complexities are profound. The dry and wet forms, each with its unique characteristics, paint a vivid picture of the challenges veterinarians and cat owners face when confronting this adversary. Yet, amidst the gloom, there are glimmers of hope, such as the benign variants of feline coronavirus that offer a stark contrast to the devastation wrought by FIP.

The quest for a cure has remained a persistent pursuit, but as of now, the battle against FIP is marked by resilience and vigilance rather than a definitive victory. The existence of a vaccine, while promising, is a decision fraught with considerations that require careful consultation with experts.

Michael R

Michael R

I'm a publisher and editor at Cat Guide 101. I imagine that since you’re here, you likely own a cat — or two! — so helping you better understand them is my aim. I'd like to invite you to check out our about page to learn more about the Cat Guide 101 story.

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