FAQs About Feline Infectious Peritonitis (FIP): A Resource for Pet Parents and Veterinarians
Feline infectious peritonitis, often referred to as FIP, is a viral infection in cats that is increasingly talked about. It’s a complex disease to diagnose, often requiring several diagnostic tests. However, in the last few years, significant research and developments have been made in the understanding and treatment of this previously fatal disease.
#1. What is Feline Infectious Peritonitis?
Feline infectious peritonitis is a viral disease in cats caused by feline coronavirus and is commonly found in the feces of cats. Research has shown that the infection is very common and the virus that causes it is contagious among cats. However, feline infectious peritonitis itself is actually not contagious between cats and not all cats infected with the virus will develop FIP.
There are two forms of feline infectious peritonitis, wet FIP and dry FIP. Wet FIP, also referred to as effusive FIP, is where fluid may accumulate in the abdomen or chest cavity of cats. It typically progresses more rapidly than dry FIP. Dry FIP, or non-effusive FIP, is where little to no fluid accumulates, but it often involves severe inflammation in one or more organs which can include the eyes, brain, liver, intestines or other organs in the cat’s body. Many cats with dry FIP will have ocular symptoms affecting the eyes, such as eye pain or watery eyes, as their only clinical signs of the infection.
#2. What Causes Feline Infectious Peritonitis?
Only about 5% of cats exposed to the virus develop feline infectious peritonitis, which can happen weeks, months or even years after initial exposure. While we do not currently know why some cats develop FIP and others don’t, it’s typically more common in:
- Cats under 2 years old
- Pedigree cats
- Cats that live in multi-cat homes
#3. What are the Symptoms of Feline Infectious Peritonitis?
When first exposed to the virus, cats usually do not show any obvious symptoms. Eventually, some cats may show mild upper respiratory symptoms including sneezing, watery eyes or nasal discharge. Others may experience mild diarrhea. Additional symptoms may include lethargy, loss of appetite and weight or a high temperature.
#4. Is There a Cure or Treatment for Feline Infectious Peritonitis?
For a while, there was no effective legal treatment for FIP. While research is still being conducted, studies have found that GS-441524 is a safe and effective treatment option for cats with FIP. The drug has been used in Australia and the U.K. for several years and is now available in the U.S. through compounding pharmacies, including Mixlab. Through Mixlab, veterinarians can prescribe GS-441524 50 mg QUADmix tablets for patient-specific use or office use if applicable in your state and a 50 mg/mL oral suspension for patient-specific use in cats.
#5. How Long Does FIP Treatment Last?
Currently, cats must be treated for a full 12 weeks on GS-441524. There is research underway to look at reducing the duration of treatment in the future. FIP symptoms should start to improve within 48-72 hours after starting treatment.
#6. What Happens During FIP Treatment?
Cats must be monitored during FIP treatment. Different types of feline infectious peritonitis require different dosages of GS-441524. Cats on GS-441524 should be weighed routinely every week, at a minimum of every two weeks, and dosage adjustments may be needed during the 12-week treatment period. Cats should be examined before stopping treatment and all assessments should ideally be normal.
#7. Are There Any Medication Contraindications with GS-441524?
Yes, corticosteroids are generally contraindicated in the treatment of FIP. However, there are some exceptions:
- Topical Corticosteroids: Cats with the eye condition uveitis may need topical corticosteroids.
- Short-term Systemic Corticosteroids: Cats with severe neurological signs may need short-term systemic corticosteroids for one to five days to reduce inflammation.
- Immune-mediated Hemolytic Anemia: Cats with FIP who develop immune-mediated hemolytic anemia may need systemic corticosteroid treatment for more than a few days.
Short-acting steroids, such as prednisolone or dexamethasone SP, can be helpful in stabilizing cats before or at the beginning of treatment for FIP. However, they should be discontinued once the cat shows improvement, usually within the first week.
#8. Are There Any Side Effects of GS-441524?
No serious adverse side effects have been reported. GS-441524 can cause mild gastrointestinal upset like vomiting or diarrhea, increased white blood cell count or increased liver enzyme values.
#9. How Do I Order GS-441524 for Feline Infectious Peritonitis?
Licensed veterinarians can now legally prescribe GS-441524, which is currently being reviewed by the FDA under GFI #256. We know that having a cat with a historically fatal condition like feline infectious peritonitis requires immediate attention. With a valid prescription, Mixlab can compound GS-441524 in 50 mg QUADmix tablets (scored twice for flexibility in dosing) or a 50 mg/mL oral suspension with convenient and free next-day delivery. Contact us to place your order today.
