Feline Infectious Peritonitis (FIP) is a disease caused by a type of coronavirus common in cats. In most cases, the coronavirus causes mild fever, and the main problem occurs when it mutates and becomes a fatal disease. Cat owners around the globe understand the helplessness caused by the disease and the challenges faced during its diagnosis. The following article will explain what is FIP in cats?
What is FIP in Cats?
What is FIP in felines? Feline Infectious Peritonitis (FIP) is a viral disease in cats all around the globe but is most common in young cats under 2 years of age. Although FIP is not so severe in the early days, it can be consistently fatal if it goes unattended. Certain strains of feline coronavirus (not to confuse with the current coronavirus) are the main reasons for FIP. Cats affected with these coronaviruses commonly do not show any severe Feline Infectious Peritonitis symptoms but may encounter periodic bouts of diarrhoea and mild fever.
In some of these cats infected with feline coronavirus, the virus mutates and alters its biological behaviour. The mutation results in white cells becoming infected, and the virus spreads throughout the body. Cats infected with FIP experience intense inflammatory reactions of FIPV (Feline Infectious Peritonitis Virus) in tissues at various body sites where these infected cells are located. Once a cat develops FIP, it is almost fatal as the disease progresses. But currently, they can treat it with the help of therapy and various clinical ways under development.
What Causes FIP in Cats?
Certain breeds of cats, like Abyssinian, Himalayan, Birman, and Ragdoll, are most likely to be affected by FIP. Cats that live in shelters or multi-cat households and cats that have undergone recent surgery or have simultaneous infections may also be infected.
The infected reasons for what FIP in cats is faeces. This faeces can infect cats through oral contact. Many cats shed viruses in their faeces, and most cats will shed viruses for a short period, but many shed viruses constantly for life.

Although the virus can not survive for more than 24-36 hours, cold conditions may preserve the virus for a long time. The virus can remain abeyant and be present in the host’s body before developing the disease. So, what causes FIP in cats is that many cats that develop FIP do not show any previous history of contact with cats infected with FIP. Most cats infected with the feline coronavirus, including the FIPV, can produce antibodies that protect them. Hence, infections, certain breed types, et., could be causes of FIP.
What are the FIP Symptoms in Cats?
Early symptoms of Feline Infectious Peritonitis shown by cats infected with FIP are unclear. Fluctuating fever, lethargy, and weight loss are some early symptoms. After 1 to 2 weeks, the FIP symptoms start to become more coherent. At these final stages of fip in cats, there can be 2 types of FIP:
#1 Effusive FIP
Due to the damage to the blood vessels by the FIPV, the fluids start leaking and accumulate in cavities. They also know the type as wet FIP because fluids accumulate in the abdominal cavity or the chest cavity, resulting in severe problems like a swollen abdomen and difficulty breathing. However, other diseases like liver disease can also lead to the accumulation of fluids.
#2 Non-Effusive FIP
In the case of non effusive fip in cats or dry FIP, fluid accumulation is little or none. The cats that develop dry FIP experience extreme inflammation in one or various organs, like the eyes, brain, liver, or other body sites. Various cats show eye problems as a clinical sign.
Once the FIP cat disease develops, felines’ health deteriorates terribly, and in some cases, the cats require euthanasia within a matter of days or weeks. But there are very few chances for an infected cat to live. In almost all FIP cases, the infected die. Many cats may develop a combination of both dry and wet FIP.
Diagnosis of Feline FIP
How can FIP be diagnosed? Since the symptoms produced during FIP are very common and occur during other diseases, too, it makes the diagnosis of FIP a little difficult. Clinical signs and problems in younger cats are not a definitive way to confirm their presence. There may be abnormalities in the blood report, but none can be specific to FIP.
However, with the help of an X-ray report, it is easy to detect effusion. If an effusion occurs, analyzing the fluid can be specifically helpful. The fluid accumulated during effusion is rich in protein. Although fluid accumulation occurs in other diseases, the fluid analysis does not always provide a perfect diagnosis for FIP. In some cases, due to other diseases, diagnosis of feline FIP becomes challenging.

They can detect the virus through PCR (polymerase chain reaction), but the test is not authoritative since PCR cannot discriminate between different coronaviruses.
The best possible way to diagnose FIP is through immunohistochemistry, which will automatically demonstrate the presence of the virus in the affected tissue. However, a cat can be severely sick to perform surgery, so in many cases, it can only make a definitive diagnosis during post-mortem examination. Performing a biopsy can also be one of the ways to reach an authoritative note.
As you can see, there is no definite way to determine FIP, and it has become one of the most challenging diseases to cure. If there is a negative report in FIP diagnosis, but there are clinical signs of fip in cats, you cannot accept that diagnosis. And, if the diagnosis gives a positive report, it cannot be authoritative.
How to Prenent FIP in Cats?
Certain vaccines are available that help in the prevention of the virus. However, the vaccine is to be provided to kittens for over 16 months. Since the time to provide the FIP vaccine cats is long, many cats get infected before the vaccination, which makes the use of the vaccine vague. Pet owners should only provide vaccines to a cat after a proper discussion with their veterinarian.
Being fatal to such an extent makes the treatment of FIP very challenging. Supportive drugs can prolong their life, but there is no definite cure for FIP in cats. Anti inflammatories for cats like prednisolone, combined with other drugs like cyclophosphamide, can help suppress the inflammation in organs and relieve the pain for a short period.
In the case of dry effusion, an experimental drug called polyprenyl immunostimulant is being investigated. Euthanasia is still the most compassionate and painless way possible for FIP-infected cats. It would help if you only gave any FIP cats treatment under the observation of an expert veterinarian.
Household Cats at Risk
The possibility of your household cats being infected with FIP is very less. However, if one of your cats has developed a FIP, others can get infected too. To minimize the risk, you should maintain good hygiene and a safe environment for your cats. Extra care should be given to kittens, avoid keeping large groups of cats and keep separate litter boxes for every cat. Ensure pet owners only bring new a month after the infected cat has died.
Conclusion
Feline Infectious Peritonitis can be a highly fatal disease because of its nature of not being distinguished and no definite way of diagnosis. Still, they can prevent it by giving extra time towards hygiene and proper fip medication for cats. Playing with the pets, giving best cat food grain free and keeping a happy environment can also help relieve their stress.