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FIP Client Information


·       What is FIP?

Feline infectious peritonitis (FIP) is a fatal disease of cats, caused by a type of feline coronavirus. Infection with coronavirus is actually very common in the UK cat population but most of the time it does not cause any problems, other than mild self-limiting diarrhoea. Uncommonly, the virus mutates (changes) within an infected cat, and it is this mutated form that causes the disease FIP.


·       How common is Feline Coronavirus?

Coronavirus is ubiquitous among cats and infection with the virus is particularly common where large numbers of cats are kept together. It is estimated that 25 to 40{fa463b3623965766ebc8e9e156e750ccbfa887373e57db871ef3d6d5e1022cef} of household cats are infected. This infection rate increases to 80-100{fa463b3623965766ebc8e9e156e750ccbfa887373e57db871ef3d6d5e1022cef} of cats kept in multi-cat households, rescue and breeding colonies.


·       How are cats infected with coronavirus?

The virus is spread by the faecal-oral route, i.e. the virus is shed in faeces into the environment and cats become infected following ingestion when grooming or eating.


Most infected cats shed the virus in faeces for a variable period of time and then stop. The cat can then become re-infected from another cat and start shedding the virus again. In contrast, some cats shed the virus continuously.


·       Why has my cat developed FIP?


Although coronavirus is the cause of FIP, infection with coronavirus does not always mean the cat will go on to develop FIP. In comparison to the number of cats infected with coronavirus the number that develop FIP is very small. It is only when the virus mutates that FIP may develop.


The cause of viral mutation is unknown. The majority of cases of FIP develop in younger cats. A poorer immune response together with other stress factors such as rehoming, vaccination, neutering, or other concurrent disease may make younger cats more vulnerable to FIP. FIP can, however, develop in any age of cat and predisposing factors or risk factors are not always evident.

Genetics may also play a role in some cases, as purebred cats appear to be at greater risk. Sometimes particular lines of a breed have a high rate of developing FIP.


·       What are the signs of FIP?


There are no clinical signs that are unique for the disease. The classic form of the disease often termed ‘wet’ FIP is characterised by a build up of yellow fluid within the abdomen (resulting in abdominal distension) and/or chest (resulting in breathing difficulties). However the presence of this fluid is NOT diagnostic for FIP, and in additional large number of cases will not have any visible fluid build up. Initial clinical signs are often very vague, consisting of lethargy and loss of appetite.

In some forms of the disease inflammatory lesions in the eye and nervous system can occur, resulting in visual disturbances and abnormal behaviour, a wobbly gait or tremors. The disease is usually rapidly progressive and ultimately fatal.


·       How is FIP diagnosed?


  1. There is no specific test for FIP. If FIP is suspected, the veterinary surgeon will perform a thorough clinical examination. The more findings that are present that are consistent with FIP, the more likely the cat does have FIP.


  1. Tissue samples can confirm a diagnosis, but often the cat is too sick for these to be undertaken and so in many cases a definitive test is only made on post-mortem


  1. If any fluid is present within the chest, abdomen or both, analysis of this fluid is one of the most useful tests that can be performed. X-rays or ultrasound scans of the chest and abdomen are useful to detect small amounts of fluid when obvious clinical signs are lacking. This fluid can then be sampled under via ultrasound guidance. The presence of fluid in the abdomen does not confirm a diagnosis of FIP as other diseases can also lead to a build up of similar fluid. If the fluid is present in both the chest and the abdominal cavity, then FIP is even more


  1. Routine blood tests are very helpful firstly in trying to exclude other causes for the clinical signs, and secondly to look for changes which may support a suspicion of FIP. Frequently the numbers of one type of white blood cell (lymphocytes) are low, there may be a mild anaemia, blood protein levels are usually very high, and sometimes blood bilirubin (pigment from old red blood cells) levels are high. All these changes are very non-specific and do not make a diagnosis of FIP, but help to increase suspicion of the disease.


  1. Cats can be tested to see if they have been exposed to coronavirus by checking for specific antibodies. However, such a coronavirus blood test is of very limited use in diagnosis. This test does not distinguish between the coronavirus encountered commonly with few associated problems, and the mutated form that causes FIP. Furthermore, some cats with confirmed FIP are actually negative for antibodies, so it can not be used to exclude


  1. In cats with neurological signs without other abnormalities, MRI scans of the brain and analysis of the fluid surrounding the brain and spinal cord can also be


Many of these abnormalities may not be present in the early stages of the disease but may become evident later. Thus some tests that give normal results may have to be repeated later.


·       Can FIP be treated?

Once clinical signs of FIP develop, it is usually fatal. Treatment is given to relieve symptoms. While there are a handful of anecdotal reports suggesting some success with newer antiviral drugs, studies have yet to show a proven benefit of any such treatments. In most cases euthanasia is recommended to avoid suffering.


·       Can you vaccinate against FIP?

There is no vaccine available in the UK. A vaccine is available in the USA but is does not appear to be particularly effective and can only be used in kittens over 16weeks of age, by which time most kittens are infected with the virus anyway.


·       How can FIP be prevented and controlled?


1.      Household Cats:

FIP is least common in household pets. The risk can be minimised by obtaining cats from a source with few cats and by keeping cats in small stable groups (less than five cats in a household). Minimising ‘stress factors’, such as rehoming, worming, vaccination and neutering happening all at once, or while the cat is suffering from other illness, may also help minimise the risk of the disease.


2.      Breeding catteries with endemic FIP:

Total eradication of coronavirus infection from catteries is extremely difficult, as the virus is so ubiquitous.


A more practical approach is elimination of coronavirus infection in newly born kittens, providing the opportunity of re-homing kittens coronavirus free. If pregnant queens are isolated one or two weeks before they are due to kitten, and then the queen is kept in isolation with her kittens (whilst employing good hygiene procedures to prevent environmental spread), a substantial number of these kittens remain negative for coronavirus.

Following weaning, the queen can be removed and the kittens still kept isolated and tested at 12 to 16 weeks of age for coronavirus antibodies. If they are negative, the isolation procedure has been successful.

This procedure sometimes fails if the queen is shedding the virus and passes it on to her kittens. It is thought that this is less likely in queens over two years and can be helped by early weaning of the kittens (at five to six weeks of age when maternally derived antibodies are still protective) and removing the queen from the environment. Good hygiene is an important part of the control of spread of the virus to kittens. Although these procedures are successful, they require considerable commitment from the breeders.

Often it is more appropriate to accept that there is endemic coronavirus infection and institute measure to try and minimise its impact. Considering that the virus is spread by the faecal-oral route, practical control measures that can be used include:


  • Having at least one litter tray for every two cats located in easy to clean/disinfect area and kept away from food and water bowls to prevent cross
  • Faeces should be removed at least once daily, accompanied by
  • Cats should be kept in small stable groups of four or less, minimising cross-contamination within a household.
  • Breeding programmes with more than 8-10 cats (including kittens) should not be undertaken in a normal household. Larger numbers require some purpose built facilities to enable proper hygiene and care to be maintained.
  • Regular brushing of the coat, particularly of long-hair cats is desirable to reduce contamination with faeces and
  • Isolation of queens and their kittens can be recommended as a means to controlling spread of coronavirus to the

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