Original article: Feline Infectious Peritonitis Differential Diagnoses
"My cat has just been diagnosed with FIP. My vet says the disease is fatal and there is no cure. How is it possible? What can I do? I feel helpless. I love my cat, I can't stand the thought of losing her… Please help. "
There are no words to describe the feeling of utter despair and helplessness. We know, we experienced it too.
You are not alone and you are not completely helpless. There are important steps you need to take now to make sure everything has been done to keep your cat healthy.
The very first step is to determine the correct diagnosis. Why? Because mistakes are common. Making a misdiagnosis can have more devastating consequences than no diagnosis. It is estimated that in 80% cats diagnosed with non-fusion (dry) FIP, the condition is caused by another, usually treatable disease. The probability of error in the case of effusion (wet) FIP is lower, but it is still very variable depending on the age and breed of the cat.
Making sure you have the right diagnosis means talking to a veterinarian, even if it should call into question his or her findings. It can save your cat's life, so just do it. Don't be stopped by the fear that you will not offend your veterinarian or that you have no medical or veterinary education, especially if your veterinarian recommends euthanasia so that your cat does not suffer unnecessarily. If it was your child, brother or yourself, would you accept the diagnosis without reservation?
The most common cause of misdiagnosis is a positive FCoV titer. Feline 95% is a carrier of FCoV (feline coronavirus). However, this does not mean that they will develop FIP. Only 5% eventually develop feline infectious peritonitis.
We often hear "My cat tested positive for FIP".
Let's be clear: there is no FIP test. It just doesn't exist. This is not how you are used to FIV or FeLV. Many people over and over again - including some veterinarians - will tell you that a cat has FIP only based on a positive FCoV titer. Even worse, some recommend euthanasia on the spot. Don't let this be the case for your cat. Let's clarify this mistake forever: A positive FCoV titer DOES NOT mean that your cat has a FIP.
FIP is a difficult disease to diagnose and the diagnosis is based more on an excretory process, especially in the dry (non-fusion) form.
Below is a table of differential diagnoses for both dry and wet forms of FIP. This list is not exhaustive. Talk to your veterinarian about these options.
Wet FIP
| Effusion | Differential diagnosis |
|---|---|
| Peritoneal (abdominal) discharge | Bacterial peritonitis Congestive heart failure Cystic kidney Glomerulonephritis Liver disease Lymphocytic cholangitis Malabsorption Neoplasia Pancreatitis Pansteatitis Parasitism Pregnancy Pyometra Toxoplasmosis Trauma Tuberculosis |
| Pleural effusion | Heart failure Chylothorax Cryptococcosis Diaphragmatic hernia Torsion of the pulmonary lobe Neoplasia (lymphoma) Pyothorax |
Dry FIP
| Clinical signs | Differential diagnosis |
|---|---|
| loss of appetite ataxia matte coat enlarged mesenteric lymph nodes jaundice lethargy eye lesions pyogranulomas pyrexia weight loss anemia neurological symptoms … Not all symptoms are listed | CNS disease Cholangitis Chronic upper respiratory tract infection Deep fungal infections: - cryptococcosis - coccidioidomycosis - histoplasmosis - blastomycosis FeLV FIV IBD Liver disease Mycoplasma (infectious anemia of cats) Neoplasia (lymphoma) Pancreatitis Kidney failure Systemic infectious diseases: - toxoplasmosis - nocardiosis - actinomycosis |
I recommend free continued of this article with a detailed description of some differential diagnoses.
EN 
SK