FIP in Cats: 8 Symptoms, Survival Rate, Treatment and Recovery Guide
Feline Infectious Peritonitis (FIP) is a serious disease caused by a mutated feline coronavirus. Common symptoms include persistent fever, weight loss, loss of appetite, lethargy, breathing difficulties, and abdominal swelling. Early diagnosis and antiviral treatment have significantly improved survival rates in affected cats.
What is FIP in cats?
Feline Infectious Peritonitis (FIP) is a serious viral disease caused by a mutated feline coronavirus. While many cats carry feline coronavirus without symptoms, some cats develop FIP when the virus mutates inside the body and triggers an abnormal immune response.
FIP can affect the abdomen, chest, eyes, brain, and internal organs. Without treatment, the disease can become life-threatening.
Early diagnosis and antiviral treatment have significantly improved survival rates in cats diagnosed with FIP.
Key Takeaway
• FIP is caused by a mutated feline coronavirus
• Wet and dry FIP have different symptoms
• FIP was previously fatal but treatment options now exist
• Early diagnosis improves survival chances
• Cats showing breathing difficulty, weakness, or abdominal swelling need urgent veterinary assessment
In cats, there are two primary forms of feline viral condition :
| Type of FIP | Common Symptoms | Why Paw Parents Should Watch Closely |
| Wet (Effusive) | Swollen abdomen, breathing difficulty, fluid buildup in chest or abdomen, low energy | Symptoms may progress quickly and become serious |
| Dry (Non-effusive) | Weight loss, persistent fever, eye changes, neurological signs, reduced appetite | Symptoms can appear gradually and may be harder to recognize |
Wet (Effusive) Feline Infectious Peritonitis
This form causes fluid buildup in the abdomen or chest. Paw parents may notice a swollen belly, breathing difficulties, reduced appetite, or low energy levels.
Dry (Non-effusive) Feline Infectious Peritonitis
This conditions affects organs such as the brain, eyes, liver, and kidneys. Cats with dry FIP may develop persistent fever, weight loss, neurological signs, or changes in vision.
What Are the Early Signs of FIP in Cats?
The early signs of FIP in cats often include persistent fever, loss of appetite, weight loss, lethargy, and reduced activity levels. As the disease progresses, some cats may develop a swollen abdomen, breathing difficulties, eye inflammation, vision changes, or neurological symptoms such as wobbling, tremors, and seizures.
Common early signs include:
- Persistent or recurring fever
- Loss of appetite
- Weight loss
- Reduced activity or lethargy
- Swollen abdomen caused by fluid buildup
- Rapid breathing or breathing difficulties
- Eye inflammation or vision changes
- Wobbling, tremors, or seizures
Because these symptoms can resemble many other illnesses, FIP can be difficult to recognise during its early stages. Veterinary assessment is recommended if symptoms persist or worsen over time.
What Does FIP Belly Look Like?
Cats with wet (effusive) FIP may develop a noticeably enlarged or swollen abdomen due to fluid accumulation within the abdominal cavity. The swelling often develops gradually and may be accompanied by weight loss, lethargy, reduced appetite, or breathing difficulties.
A swollen abdomen can also be caused by other medical conditions, which is why veterinary assessment is important if you notice unusual abdominal enlargement in your cat.
Cases We Commonly See at Starlight Veterinary Hospital
At Starlight Veterinary Hospital, many paw parents initially visit us because their cat has stopped eating, developed a persistent fever, or appears less active than usual. In some cases, abdominal swelling or breathing difficulties become noticeable as the condition progresses.
At Starlight Veterinary Hospital, cats suspected of FIP are often brought in for symptoms such as:
- Persistent fever
- Reduced appetite
- Weight loss
- Lethargy
- Abdominal swelling caused by fluid accumulation
- Breathing difficulties
Many paw parents initially assume these symptoms are minor or temporary. However, because FIP can share similar signs with other illnesses, diagnostic testing is often needed to identify the underlying cause and guide appropriate treatment.
Can Cats Survive FIP?
Yes. Many cats diagnosed with FIP can survive when diagnosed early and treated with appropriate antiviral medications such as GS-441524. Survival rates have improved significantly in recent years, particularly when treatment begins before severe complications develop.
The prognosis depends on factors such as the type of FIP, the organs affected, and how quickly treatment is started. Early veterinary assessment remains one of the most important factors influencing recovery outcomes.
What Is the Survival Rate of Cats With FIP?
The survival rate of cats with FIP has improved significantly following the availability of antiviral treatments such as GS-441524. Cats diagnosed and treated early often have a much better prognosis compared to untreated cases.
Recent studies have reported encouraging outcomes in cats treated with antiviral medications such as GS-441524, with many cats achieving remission when treatment is started early.
However, outcomes vary depending on disease severity, the organs affected, and how quickly treatment begins. Early veterinary assessment remains one of the most important factors influencing recovery outcomes.
What Causes FIP in Cats?
FIP is caused by a mutation of feline coronavirus (FCoV) within a cat’s body. While feline coronavirus is common among cats, only a small percentage develop FIP after the virus mutates and triggers an abnormal immune response.
The exact reason why the virus mutates is not fully understood. Factors such as age, immune status, stress, and environmental conditions may contribute to the risk of developing FIP.
Is FIP Contagious Between Cats?
FIP itself is not considered contagious between cats. However, the feline coronavirus that may later mutate into FIP can spread through close contact, shared litter boxes, and contaminated environments.
How Do Cats Get FIP?
Cats usually become exposed to feline enteric coronavirus (FECV) through close contact with infected environments. Common sources include:
- Shared litter boxes
- Contact with infected feces
- Grooming between cats
- Shared food and water bowls
- Multi-cat households
Most cats exposed to feline coronavirus never develop FIP. The disease develops only when the virus mutates within the cat’s body.
How Do Veterinarians Diagnose FIP?
Diagnosing FIP can be challenging because the symptoms often resemble other diseases. Veterinarians typically use a combination of clinical examinations, blood tests, imaging studies, and laboratory findings to assess cats suspected of having FIP.
How Veterinarians Diagnose FIP
| Diagnostic Test | Purpose |
| Physical Examination | Assess overall health and symptoms |
| Blood Tests | Evaluate inflammation and organ function |
| Ultrasound | Detect fluid accumulation or organ changes |
| X-rays | Assess chest or abdominal abnormalities |
| Fluid Analysis | Evaluate abnormal fluid associated with wet FIP |
| Ongoing Monitoring | Track response and disease progression |
When Should You Bring Your Cat to a Vet for Suspected FIP?
You should seek veterinary attention as soon as possible if your cat develops symptoms that may be associated with FIP, especially if they persist or worsen over time.
Signs that warrant veterinary assessment include:
- Persistent or recurring fever
- Loss of appetite
- Unexplained weight loss
- Swollen abdomen
- Difficulty breathing
- Eye inflammation or vision changes
- Wobbling, tremors, or seizures
- Sudden changes in behaviour or activity levels
Because FIP can progress and affect multiple organs, early diagnosis may provide more treatment options and improve overall outcomes.
At Starlight Veterinary Hospital, our veterinarians use clinical examinations, blood tests, imaging, and other diagnostic tools to investigate cats showing signs consistent with FIP and recommend appropriate treatment plans.
FIP Symptoms and Recommended Veterinary Action
| Symptom | Recommended Action |
| Persistent fever | Schedule a veterinary assessment |
| Loss of appetite | Schedule a veterinary assessment |
| Weight loss | Schedule a veterinary assessment |
| Swollen abdomen | Schedule a veterinary assessment |
| Difficulty breathing | Emergency veterinary care |
| Seizures | Emergency veterinary care |
| Collapse | Critical emergency |
What We Commonly See in Clinical Practice
At Starlight Veterinary Hospital, our veterinary team occasionally sees cats presented with ongoing fever, reduced appetite, low energy levels, abdominal swelling, or unexplained breathing changes. Because these signs can overlap with several medical conditions, further assessment may be needed to determine the underlying caus
Clinical evaluation for suspected virl infection, cases may include:
- Physical examination
- Blood tests
- Diagnostic imaging such as X-rays or ultrasound
- Ongoing monitoring and supportive care
Early veterinary assessment may help identify concerns sooner and guide the next steps for your cat’s care.
If your cat is showing unusual symptoms, appointments can be scheduled through the Pet Universe app for a smoother consultation process.
FAQ
What owners actually ask?
Can Indoor Cats Get FIP?
Yes. Indoor cats can develop FIP if they have previously been exposed to feline coronavirus (FCoV). While indoor cats may have lower exposure risks than outdoor cats, FIP can still occur when the virus mutates within the cat’s body.
Is FIP Painful for Cats?
FIP can cause discomfort depending on the organs affected. Some cats may experience abdominal swelling, breathing difficulties, inflammation, or neurological symptoms that can affect their quality of life. Veterinary assessment is important if your cat appears uncomfortable or unwell.
What Age Are Cats Most Likely to Develop FIP?
FIP is most commonly diagnosed in young cats under two years of age. However, cats of any age can develop FIP, particularly if they have been exposed to feline coronavirus and possess other risk factors.
Can Kittens Get FIP?
Yes. Kittens are considered one of the highest-risk groups for FIP. Their developing immune systems may make them more susceptible to the disease, particularly in multi-cat environments where feline coronavirus is more common.
Can Cats Recover from FIP?
Yes. Many cats diagnosed with FIP can recover when diagnosed early and treated with appropriate antiviral medications such as GS-441524. Treatment outcomes vary depending on disease severity, affected organs, and how quickly treatment begins.
How Quickly Does FIP Progress?
The progression of FIP varies between cats. Some cases develop gradually over weeks, while others worsen more rapidly. Early veterinary assessment is recommended whenever symptoms such as fever, weight loss, or abdominal swelling are observed.
Is FIP an Emergency?
FIP should be assessed by a veterinarian as soon as possible, especially if your cat develops breathing difficulties, seizures, severe lethargy, or rapid abdominal swelling. Early diagnosis may improve treatment options and outcomes.
Can Dogs Catch FIP from Cats?
No. FIP is a disease that affects cats and is not considered contagious to dogs. However, if your pet is showing signs of illness, veterinary assessment is still recommended.
How Long Can Cats Live with Untreated FIP?
Without treatment, FIP is often progressive and can become life-threatening. Survival times vary depending on the type of FIP and the organs affected, but early diagnosis and treatment provide the best opportunity for improved outcomes.
Last reviewed: May 2026
