Sadly there is no one way of preventing your cat from FIP. A complex series of events accumulate into a perfect storm, causing FIP. Here, we summarize what FIP is, the symptoms, and how you can reduce the chances of your cat suffering FIP – although the risks can never be fully eliminated.

What is FIP?

FIP means Feline Infectious Peritonitis. Its name describes a common symptom of excess fluid in the peritoneum (lining of the abdomen), just one of many possible outcomes of this condition, so a little misleading.

What is it caused by?

It is caused by a virus called a Coronavirus (FCoV) which is infectious and caught when a cat eats it. The most common time for infection is between 5-8 weeks of age and spread by an infected mother grooming her kittens. Litter trays are another big source of infection. This virus so common that 25-40% of household cats have been infected, and 80-100% of cats in households with many cats. Cats may have no symptoms at all, or mild diarrhoea. Every cat will react to the virus differently. Some will fight it and get over it, others may do this but get it again, some remain infected and shed this virus in their faeces.

Only a small percentage (5-10%) of these cats will go on to develop FIP.

How does FCoV turn into FIP?

This is where it gets complicated.

Under certain circumstances this virus can mutate, changing into a different strain of the virus called Feline Infectious Peritonitis Virus (FIPV). It is this strain that can cause serious disease. It has the potential to move outside the gut and if there isn’t a good immune response then FIP can occur. A cat with a weak immune system or under stress will be more susceptible to FIP.

Once a cat develops FIP it is fatal, often rapidly so.

What are the signs?

WET FIP is where the FIPV causes damage to the blood vessels which start to leak fluid. In the chest this causes breathing issues, and in the abdomen this causes the belly to swell with fluid.

In DRY FIP long term damage to blood vessels in many organs causes reactive tissue to form. Signs can vary a lot, depending on which organ it forms in. If it forms in the brain it may cause wobbliness, or forming in the eyes may cause vision issues.

A cat can have a mix of the two.

We look for patterns in the history, examination and samples to make a diagnosis. Confirmation can only be made by looking at tissue samples. Since these cats are so sick, we cannot risk anaesthesia for sampling, and it is often only confirmed after death. Any treatment given is aimed at supporting the cat through the illness, and reducing suffering. It is incurable.

Is there no vaccine against FCoV/FIP?

There is a vaccine against FoCV available in some countries (not the UK), but it can’t be given until 16 weeks of age. Most cats will have been exposed to the FCoV virus by then so is not that useful.

My cat died of FIP, when is it safe to get another cat?

FCoV is easily killed, so disinfect exposed areas with bleach. Throw away used items such as litter trays, food bowls, toys and beds. Then wait at least 6 weeks.

If you have other cats the situation is more complex. Bringing another cat into the house may cause stress for example, and extra shedding of the virus. It is best to speak to one of our vets, who can help you decide.

What if I have many cats, is there nothing I can do to prevent FIP?

It is impossible to eliminate FCoV completely, especially where there are many cats. The key is to understand and influence the two main factors which can encourage the fairly benign FCoV virus to cause FIP in your cats.

These two factors are the level of virus the cat is exposed to and the state of the immune system and stress at the time of meeting.

The following is mainly for breeders and rescue centres, but it is still useful advice, especially if you have lots of cats.

How can I reduce the levels of virus?

  • House cats individually or in smaller, isolated groups.
  • Review hygiene and cleaning practices. The virus is easily destroyed by disinfectants. Talk to our vets about the best products and cleaning methods.
  • Clean and disinfect litter trays daily and if possible have one tray, food and water bowl for each cat, or at least separate ones for adults and kittens.
  • Keep litter trays away from food and water sources.
  • Avoid multiple litters of kittens at any one time. Pregnancy and giving birth increases stress. Stress increases shedding of the virus. If there is an outbreak, stop breeding. Stop breeding from queens or toms that have produced FIP kittens and isolate all queens just before they are about to give birth until kittens are homed.

Stress and health

Stress has a huge effect on mental wellbeing and immune system health and physical effects on other body systems. Make sure cats have their own space to reduce conflict, their own food, water and litter tray source. Talk to our vets about signs of stress and how to reduce it. Stress is a contributing factor to many conditions, so looking at stress levels in your cats is not just about FIP prevention. Stress also increases shedding of the virus so increased levels of virus in the area.

Get your cats vet-checked regularly to try and pick up any health issues early.

In summary, to help prevent this awful disease it is important to understand contributing factors. Reducing the number of cats living in the same area and reducing stress, alongside good daily disinfection routines, goes a long way to reduce the chance of this virus changing from one that delivers only mild symptoms to fatal ones.