FIP in cats: What is feline infectious peritonitis?
First Published: 18/02/2019
Last Updated: 21/10/2024
Feline infectious peritonitis (FIP) is a rare but often serious illness in cats, caused by a mutation of a common feline coronavirus. It happens when a specific type of feline coronavirus called FCoV mutates and interacts with your cat’s immune system. First identified in 1963, FIP has become more concerning in recent years. The disease can be tricky to diagnose because of its wide range of symptoms and the absence of a single, definitive test. It also poses challenges when it comes to treatment.
Brief summary
- FIP is a rare but serious coronavirus-related disease in cats
- Symptoms range from fever and lethargy to abdominal swelling and neurological problems
- It’s more common in multi-cat households and challenging to diagnose
- Recent advances have made treatment possible, although not straightforward
- Prevention focuses on cleanliness, stress reduction, and hygiene, especially in multi-cat homes
What are FIP in cats symptoms?
There are two types of FIP — wet and dry. Cats with either type may show symptoms such as fever, weight loss, lethargy, and abdominal swelling. Neurological symptoms like incoordination and seizures can also occur, alongside gastrointestinal issues such as diarrhoea and vomiting.
Wet FIP also causes fluid retention in the stomach, chest, or both. Fluid in the chest often leads to difficulty breathing, while fluid in the stomach can cause the abdomen to bloat.
Dry FIP can cause inflammatory lesions to form in the cat’s vital organs. If these affect the kidneys, they can cause vomiting, as well as excessive thirst and urination. If they affect the liver, this can go on to cause jaundice. Dry FIP can also affect your cat’s eyes and nervous system.
Read more: What are the symptoms, causes and vaccine for cat flu?
When should I see a vet about feline infectious peritonitis?
It's really important to detect FIP early. If your cat is experiencing ongoing health issues, such as chronic weight loss or persistent fever, FIP may be the cause. Diagnosing FIP requires a thorough approach, taking into account your cat’s medical history, symptoms, and a range of diagnostic tests.
FAQs about FIP
| Question | Answer |
|---|---|
| Can a cat with FIP survive? | While FIP is almost always fatal if left untreated, new antiviral treatments like remdesivir and GS-441524 have greatly improved survival rates. These treatments are promising but require a long course of medication, which can be expensive. |
| What are the final stages of FIP in cats? | In the advanced stages of FIP, cats may develop symptoms such as difficulty breathing due to fluid in the chest, neurological problems, eye issues, and jaundice caused by liver damage. |
| What is the life expectancy for a cat with FIP? | Without treatment, the outlook for FIP is usually poor, with many cats passing away within weeks to months. However, with new antiviral treatments, some cats are able to survive, although treatment requires a lengthy and costly medication regimen. |
| Is FIP in cats contagious? | FIP itself isn’t contagious, but the feline coronavirus that can mutate into FIP is highly infectious between cats. The virus that leads to FIP doesn’t typically spread directly from one cat to another. |
| How do cats get FIP? | FIP develops when a benign feline coronavirus mutates within a cat’s body. Cats generally catch the virus through contact with infected faeces, especially in multi-cat households. While transmission from mother to kittens can occur, not all FCoV infections turn into FIP. |
| What are the treatment options for FIP? | New treatments for FIP include oral medication GS-441524 and the injectable version, remdesivir. Treatment usually lasts for 12 weeks and can be expensive, but over 85% of cats show improvement. Learn more below. |
| Can cat owners prevent FIP? | Preventing FIP involves reducing the spread of feline coronavirus. This means maintaining good hygiene, isolating sick cats, avoiding overcrowded multi-cat homes, and managing stress to help lower the risk of infection. |
| Can humans catch feline coronavirus or FIP? | No, humans can't catch feline coronavirus or FIP. These viruses are specific to cats and do not affect people. |
Read more: Why is my cat being sick?
Can FIP in cats be treated?
Up until recently, there were no treatment options for FIP, and management focused on symptomatic treatment and relieving discomfort. However, there are now two licensed treatments for FIP in the UK. GS-441524 is a tablet medication, and its parent drug remdesivir is an injectable form. Treatment is generally performed for 12 weeks, but repeat treatment courses may be required. This is, therefore quite a commitment, and the medications can be very expensive. Cats will need close monitoring during treatment, including regular examinations and blood tests. A successful outcome is not guaranteed of course, and there is still a lot of research ongoing, but current estimates show that over 85% of cats respond to treatment following at least 12 weeks of treatment, with long-term remission.
Read more: How to introduce a new cat to your home
Any studies into FIP?
One study into FIP by Katrin Hartmann investigated FIP. It showed that while many cats catch the FCoV virus, only a few get FIP. The study found that a cat's genes and living conditions can affect their chances of getting FIP, with young and weaker cats at higher risk. Making an effective vaccine for FIP is difficult, and current treatments don't work well. The study also stressed the importance of finding better ways to spot FIP early and manage cat groups to stop the spread of FCoV and lower the chances of cats getting FIP.
Another study examined the new oral drug for curing FIP in cats. The researchers tested its effectiveness and side effects in 18 cats with natural FIP and found the drug had strong virus-killing power in lab tests and significantly improved the cats' health in a few days without severe side effects. All the cats fully recovered after 84 days of treatment.
Numerous studies into FIP are currently being carried out, including at the University of Edinburgh's Royal (Dick) School of Veterinary Studies and UC Davis. Their aim is to improve the diagnosis, treatment, and prognosis of FIP.
Read more: Importance of routine health checks for cats
Why did an outbreak of FIP in cats in Cyprus hit the news?
A deadly outbreak of feline coronavirus in Cyprus in 2023 killed an estimated 300,000 cats. The Cyprus strain, F-CoV-23, is considered especially problematic for two reasons. Firstly, it's highly contagious, and secondly, feline coronavirus usually needs to mutate to cause FIP, but this strain may be able to cause infectious peritonitis without mutation, leading to much higher case numbers of FIP than usual.
The first known F-CoV-23 case in the UK occurred in a cat from Cyprus. Concerns remain about further UK spread, given how many people holiday on the island. Experts are urging caution for those exposed to cats in Cyprus. The British Veterinary Association recommends taking precautions, such as cleaning suitcase wheels and shoes before re-entry into the UK, to avoid bringing the virus into the country.
Want advice on FIP?
For expert advice on feline infectious peritonitis get in touch with your local vet.
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