FIP in cats
What is FIP and how does infection with FCoV?
FIP stands for feline infectious peritonitis, which is caused by a virus called feline coronavirus (FCoV). This is different from the human coronavirus and causes a different form of disease.
Feline coronavirus is very common, and most cats have been exposed to the virus in their lifetime. It is estimated that 25-40% of household cats are positive for FCoV, but this is higher in high cat population areas. The virus replicates in the intestines and is shed in the faeces, where it can survive for several days. Infection occurs after ingestion of the virus, generally by licking fur which has been contaminated by faeces.
FIP can occur in cats of any age; however, it is most common in young cats (less than two years old) or a small portion of older cats (older than 10 years old). Cats in breeding colonies or in high-population households seem to be at an increased risk.
How does FCoV cause FIP?
Most strains of FCoV do not cause severe disease or may cause a transient gastrointestinal upset only. However, in some cats the virus undergoes a spontaneous mutation while replicating in the intestines. This mutated form of the virus causes FIP by invading important cells of the immune system (macrophages) and spreading throughout the body causing severe inflammation. Stress appears to be a major risk factor in the development of FIP.
What are the clinical signs of FIP?
The clinical signs of FIP are non-specific and unfortunately can mimic other disease processes. Generally, most cats will have a high temperature (fever), lethargy, and reduced appetite. There are two main forms of the disease, known as ‘wet’ and ‘dry’ FIP, however, the infection can also present with purely neurological or ocular signs. In many cats, the signs that develop that are a combination of these forms.
What is dry FIP?
The dry form of FIP does not cause fluid accumulations however it does cause inflammation throughout the body in blood vessels and in organs such as the kidneys, liver, or lungs. This means that a wide range of clinical signs may be observed. In some cats, inflammation may occur only in the central nervous system (causing neurological signs such as imbalance/incoordination, reluctance to walk/jump, tilted head) or only in the eyes (causing poor vision, cloudy appearance to the eyes, abnormal pupil sizes).
What is wet FIP?
This form of FIP is characterised by abnormal accumulations of fluid in the abdomen and/or chest, surrounding the organs, caused by inflammation of the blood vessels. This can cause distension or bloating of the abdomen as well as breathing difficulties. The fluid is typically a clear-yellow colour and contains a lot of protein.
Which cats are most at risk from FIP?
FIP can occur in any cat of any age however it is most common in young cats, with 80% of cases occurring in cats less than two years of age. FIP is also most common in breeding colonies and high population households, possibly, in part, due to the stress of over-crowding dampening the immune response.
How is FIP diagnosed?
FIP can be challenging to diagnose, in part because of the non-specific clinical signs and in part because of the lack of a simple diagnostic test.
To make a diagnosis of FIP vets must use a combination of clinical signs, blood testing, fluid testing, and biopsies or needle samples from the internal organs.
Your vet may become suspicious of FIP if your cat shows high white blood cell counts and high blood protein (globulin) levels. Additional abnormalities such as increased liver enzymes or increased kidney markers can also be observed. More specific tests look for an inflammatory marker in the blood and the presence of the virus in blood, fluid, or tissue biopsies. Unfortunately, these tests cannot distinguish between the non-mutated and mutated types of coronavirus which is why we often use a combination of tests.
Can FIP be treated?
FIP is a challenging disease to treat and can be rapidly fatal. Recently, an antiviral drug called remdesivir became legally available to vets in the UK for treatment of FIP. his treatment has shown promising results, with 80-95% of cats reported to respond positively to treatment and achieving ‘remission’ from FIP. The treatment is recommended daily for at least 12 weeks (via injections and/or tablets).
Most cats that receive remdesivir will improve clinically within the first few days of treatment, however, there is a subset of patients (~8%) that sadly will have a relapse of disease during the initial treatment course or after. As the treatment is only newly available, we currently do not know more about the long-term prognosis after completing treatment.
How can FIP be prevented?
The risk of FIP can be minimised by obtaining your pet from a source with relatively few cats and by avoiding large groups of cats. It is recommended within a household to have numerous easy-to-clean litter trays and to keep litter trays separate from food and water bowls. Maintaining good hygiene around litter trays and feeding is essential, and stress should be avoided where possible.
In some countries, there is a vaccine for feline coronavirus; however, this is not available in the UK. The vaccine cannot be given to cats under 16 weeks of age, by which point most cats have already been exposed to feline coronavirus.
Cat Health Information – Find out more:
Menu
Menu
