What Are the Early Symptoms of FIP That Cat Owners Should Know?
- CUREFIP.COM
- 2 days ago
- 5 min read
Feline Infectious Peritonitis (FIP) is one of the most misunderstood yet increasingly treatable diseases in cats. For years, FIP was considered fatal, but advancements in antiviral therapy have changed the outlook — thousands of cats across the world have recovered and now live healthy lives again.
Recognising the early FIP cats symptoms is essential. The sooner you act, the greater your cat’s chance of recovery. Unfortunately, many cat owners mistake these early signs for common illnesses, delaying life-saving treatment.
At CureFIP, we’ve helped more than 87,000 cats worldwide recover from FIP using science-backed antiviral therapy. This guide will help you identify early FIP symptoms, understand the different types of FIP, and know what to do next.
What Is Feline Infectious Peritonitis (FIP)?
Feline Infectious Peritonitis (FIP) is a viral disease caused by a mutation of the feline coronavirus (FCoV) — unrelated to the human COVID-19 virus.
Most cats exposed to FCoV experience only mild digestive problems such as soft stool or diarrhoea. However, in some cats, the virus mutates inside the body and triggers an abnormal immune response, leading to FIP.
Importantly, FIP itself is not contagious. The regular feline coronavirus can spread among cats, but once it mutates into FIP, it cannot be transmitted. This means a cat diagnosed with FIP does not endanger other cats in the same household.
Common Early Symptoms of FIP in Cats
So, what are the first feline infectious peritonitis symptoms in cats to watch for?
Here are the most common early signs, which may seem minor at first but are important indicators:
General Early Symptoms (All FIP Types)
Persistent fever that does not respond to antibiotics
Loss of appetite or refusal to eat
Weight loss, even with normal food intake
Lethargy or low activity
Rough or dull coat, lack of grooming
Types of FIP
FIP in cats can appear in two main forms — Wet FIP (Effusive) and Dry FIP (Non-effusive).If untreated, both can progress into Neurological FIP or Ocular FIP.
Wet FIP (Effusive Form)
Wet FIP develops when fluid builds up in the abdomen or chest cavity.Cats with this type often appear bloated or pot-bellied and may have difficulty breathing due to pressure from fluid accumulation.
Sometimes, the abdomen feels tight or firm even when filled with fluid. Your vet can extract and test this fluid to help confirm the diagnosis.
Common symptoms:
Swollen or distended belly
Breathing difficulties or panting
Reduced appetite and energy
Occasional coughing or weakness
Dry FIP (Non-effusive Form)
Dry FIP affects internal organs such as the liver, kidneys, or lungs without causing visible fluid build-up.Affected organs may become enlarged or firm, which can be detected through a veterinary examination.
Common symptoms:
Gradual weight loss despite eating normally
Persistent fever and general fatigue
Pale gums or yellowing (jaundice) due to liver involvement
Because Dry FIP progresses slowly, it’s often diagnosed later than Wet FIP.
Neurological FIP
When FIP affects the central nervous system, it’s known as Neurological FIP.Symptoms can vary depending on which part of the brain or spinal cord is affected and may include:
Tremors or seizures
Loss of balance or unsteady walking (ataxia)
Muscle weakness or partial paralysis
Behavioural changes or reduced alertness
Difficulty jumping or walking straight
Nystagmus (involuntary eye movement) — a symptom increasingly common in neurological FIP
Cats with neurological FIP may appear disoriented or stumble when walking.
Ocular FIP
Ocular FIP occurs when the virus affects the eyes.This form causes visible eye changes such as:
Eye inflammation (uveitis)
Cloudiness or change in eye colour
Reduced or lost vision
Cataracts or inflammation around the iris and lens
Anisocoria (unequal pupil sizes) — where one pupil is larger than the other
Ocular symptoms may occur alone or alongside other FIP signs. While supportive care can ease discomfort, antiviral therapy is needed to stop disease progression.
Early symptoms of FIP in cats include persistent fever, appetite loss, and weight loss. As the disease advances, cats may show fluid build-up (Wet FIP), organ damage (Dry FIP), or neurological and eye-related signs.
FIP Symptoms in Kittens vs. Adult Cats
Kittens and young cats (under two years old) are more vulnerable to FIP because their immune systems are still developing.
Signs of FIP in Kittens:
Sudden tiredness or reluctance to play
Failure to gain weight or rapid weight loss
Swollen belly that feels soft or fluid-filled
Quick progression from mild to severe illness
Adult Cats
Adult cats often show a slower progression.They may appear less playful, eat less, lose weight gradually, or hide more frequently.
Because kittens deteriorate faster, even mild FIP signs should be investigated immediately.
📖 Related: How Long Can a Cat Live with FIP?
When to See a Veterinarian
If your cat has persistent fever, appetite loss, or unusual behaviour, visit a veterinarian familiar with FIP as soon as possible.
Common diagnostic tests include:
Complete Blood Count (CBC) — checks for inflammation or anaemia
A/G Ratio (Albumin/Globulin) — low levels may indicate FIP
Rivalta Test — evaluates abdominal or chest fluid
PCR or Immunohistochemistry tests — confirm the virus’s presence
Although no single test is 100% accurate, combining results and symptoms provides strong diagnostic evidence.
Early diagnosis is crucial — starting antiviral treatment as soon as possible significantly improves recovery chances.
What To Do If You Suspect FIP
If you suspect your cat has FIP, don’t panic — FIP is no longer a hopeless diagnosis.
The first step is to contact a veterinarian experienced with FIP treatment.Some traditional vets may still believe FIP cannot be cured, but thousands of successful recoveries prove otherwise.
At CureFIP, we offer GS-441524 based antiviral therapy, the most effective and scientifically proven treatment for FIP.Our dedicated team has guided over 87,000 cats globally to recovery and remission.
Next Steps:
Consult your veterinarian and request FIP-specific tests.
Contact CureFIP for professional guidance and treatment planning.
Monitor your cat’s progress carefully throughout treatment.
👉 Learn more about proven treatment options and real recovery stories at CureFIP.com.
FAQs About FIP in Cats
1. What are the first signs of FIP in cats?
The first signs often include fever, appetite loss, and lethargy. Over time, cats may develop fluid build-up, weight loss, or eye and neurological problems.
2. Can FIP be cured?
Yes. With GS-441524 antiviral therapy, most cats recover completely. Thousands of FIP cases have been successfully treated through CureFIP.
3. How long can a cat live with FIP?
Without treatment, cats usually survive for only a few weeks or months.With timely antiviral therapy, recovery rates now exceed 90%.
4. What should I do if my cat shows symptoms of FIP?
Seek veterinary care immediately and contact CureFIP for expert support.Early treatment offers the best chance of recovery.
5. Is FIP contagious to other cats?
No. While the feline coronavirus (FCoV) can spread, the mutated FIP form is not contagious.
6. Can FIP return after treatment?
Recurrence is rare, especially after completing the full course of treatment. Regular follow-ups are advised post-recovery.
Conclusion
FIP was once a devastating diagnosis for cat owners, but today it’s a treatable and curable disease.By recognising early FIP cats symptoms — such as fever, appetite loss, or a swollen belly — you can act quickly and save your cat’s life.
At CureFIP, we’ve helped thousands of cats recover fully through advanced antiviral therapy and compassionate care.
If you suspect FIP, contact CureFIP.com today — because early detection saves lives.
Contact CureFIP
Website: www.curefip.com
Email: europe@curefip.com
WhatsApp: +1-646-653-2654
Instagram: @curefipawareness