FIP is very hard to diagnose in so many cases. Even some vets find it hard. There are no set rules as every cat can present differently but there are some general guidelines.

Firstly it is important to understand that FIP and what it is.

Feline Infectious Peritonitis is a common and highly fatal coronavirus (FCov) disease in cats. It is caused by the feline enteric corona virus (FECV). FECV is similar to corona virus causing diarrhoea or bronchitis in humans, as well as other animals. In about 10% of cats, mainly kittens, the enteric corona virus mutates attacking the gut lining causing it to ooze. It can lie dormant and later attacks the lining of the blood vessels, the brain and eyes.

There are two main forms of FIP plus two types Ocular and Neuro.

WET (effusive)

This occurs in approx 75% of all FIP cases.

Symptoms of wet are:

  • Antibiotic resistant fever
  • Diarrhoea
  • Anaemia
  • Depression
  • Reduced appetite
  • Weight loss
  • Fluid in the abdomen and/or chest


Symptoms of dry are:

  • Failure to thrive
  • Poor hair, coat, skin
  • Bouts of diarrhoea
  • Weight loss

Cats with dry FIP are more clinically ill and harder to diagnose. Cats can also have symptoms of brain or eye issues especially with the dry form Brain issues are known as Neuro issues. They often have neurological signs such as difficulty walking, getting themselves in and out of a litter tray, walking in to doors and walls, even licking the floor or the walls.

Eye issues are also seen especially with dry FIP. The eyes can be very watery, have a discharge, may become milky and look like they have a film over them. This is referred to as Ocular FIP.

FIP can still be hard to diagnose. Blood tests can pick up changes resulting in a diagnosis. These include elevated white blood blood cell count, elevated protein and globulin levels and low albumin. It is not necessary to have extreme testings done like MRI, CT Scans or spinal taps. These are extremely expensive and the cost of these could be better spent on treatment.

Once you have a diagnosis it is vital you decide as quickly as possible what you want to do; treat or not to treat.

Palliative care can be given to your cat by way of medication to make it as comfortable as possible. It’s lifespan will depend on the severity of the FIP.

Euthanasia: some choose to euthanise almost immediately.

Treat: this decision must be made knowing all the facts.

What is involved if I choose to treat?

Firstly we recommend you have a good support network around you including support groups like FIP Warriors Australia and New Zealand.

Some vets are now authorised to administer treatment. (a list of treating vet can be found here in each State).

Firstly most treating vets will admit your cat in to hospital where it will have an IV inserted and will start on a drug called Remdesivir. This drug is administered daily at approx the same time through the IV straight in to the blood supply. It may require a chest drain to be inserted if it’s breathing is laboured through the fluid build up in the chest cavity. Vets do not drain the fluid from the abdomen unless in extreme circumstances. If your cat is not eating a feeding tube may also be inserted. These are normally left in for up to 14 days. Once the cat is stable normally after three days and three doses of Rem, it is allowed to go home. This is where you have to take over and give your cat a daily injection of Rem. Vets will show you how to do this. It is important to follow their instructions and understand the importance of documenting everything.

Some people find it easy, others very difficult.

You can now legally switch to GS pills which are given daily but we do not recommend these are given until four weeks in to treatment. Some cats are easy to inject, others difficult. Some vets prescribe a drug called Gaberpentin which is a pain blocker to be given up to two hours prior to injection times to help with the pain.

Treatment is a minimum of 84 days and blood tests are required to be done around day 42 and again day 84 to monitor progress. If your cat has progressed well enough up to 84 days you can stop treatment and go in to an 84 day observation period where just monitoring is all that is required. After 84 days of observation a blood test is done and if all is good the cat is declared cured of FIP.

Occasionally cats can relapse through observation and your treating vet will discuss with you what action may be necessary eg. another 3/4 weeks of treatment.

Some cats need their dosage of treatment changed during the course of the 84 days due to weight gains, neuro or ocular being seen. The vet will guide you on this.

It is good to familiarise yourself with a couple of good websites in the reference pages of this website or the Warriors group.

Some cats have a very smooth transition from diagnosis to treatment to observation all without any further issues. Others have a few hiccups with veterinary intervention required to get the cat back on track.

Interestingly, pet health insurance companies are now seeing FIP as a medical disease which it is and are paying for the treatment. This is a huge relief to many and shows the importance of keeping your cat pet health insured. It’s a good idea to liaise with your pet cover to check if you find yourself in this situation.

Remember help is available and we suggest you contact your State Committee member for further help and support.