Understanding Feline Infectious Peritonitis (FIP):

Feline Infectious Peritonitis (FIP) is a severe and often fatal disease caused by certain strains of the feline coronavirus (FCV). FIP primarily affects the abdominal lining (peritonitis) and can lead to fluid accumulation, inflammation, and severe organ damage. 

The disease manifests in two forms: the “wet” form, characterized by fluid buildup in the abdomen or chest, and the “dry” form, which leads to the formation of granulomas in organs like the liver, kidneys, and brain.

Symptoms of Feline Infectious Peritonitis

Feline infectious peritonitis can be challenging to diagnose because its symptoms can be similar to those of other diseases. The symptoms can also vary depending on whether the disease is in its “wet” or “dry” form. See common symptoms of FIP below. 

Cats with FIP often have a fever that does not respond to antibiotics. 

Affected cats may become very lethargic and show a lack of energy. 

Significant and unexplained weight loss is common in cats with FIP. 

Cats may refuse to eat, leading to further weight loss and weakness. 

Fluid buildup in the abdomen can cause a swollen, pot-bellied appearance. 

Fluid in the chest can lead to breathing difficulties. 

Jaundice, increased thirst, and urination may occur if the liver or kidneys are affected. 

Cats may show signs such as unsteady gait, seizures, or behavioral changes if the brain is involved. 

Eye inflammation and other eye-related issues can occur. 

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Introducing GS Tablets from Avrio Pharmacy:

Avrio Pharmacy is proud to introduce compounded GS tablets, a promising treatment option for cats suffering from feline infectious peritonitis. GS-441524 (GS), the active ingredient in our GS tablets, is an antiviral drug (nucleoside analog) that has shown significant success in curing cats with FIP in field trials conducted at UC Davis by Dr. Niels Pedersen and his team. However, it’s important to note that while GS tablets have shown promise, they do not guarantee a cure for every cat with FIP. 

Key Features of Avrio Pharmacy’s GS-441524 Tablets:

Ease of use: Compounded GS-441524 comes in a convenient 50 mg tablet that can easily be divided into quarters. This allows for precise dosing tailored to your cat’s weight and clinical improvement, making it simple to adjust the dosage as needed without the hassle of ordering multiple strengths.

Promising Results: GS-441524 has demonstrated success in clinical trials, providing a potential treatment option for cat owners and veterinarians.

Convenient Dosing: Avrio’s GS tablets are easy to administer, can be broken into quarters, and are compounded to help ensure cats receive the correct dosage with minimal stress.

Quality Matters: Avrio only sources the active ingredient GS-441524 from FDA registered wholesalers, inspects all certificates of analysis prior to use, and has undergone internal quality measures to ensure our compounding process.

GS Treatment Protocol:

 

Treatment Duration: Based on Dr. Pedersen’s original field trial, the recommended treatment is at least 12 weeks (84 days) of daily subcutaneous injections or oral medication. Blood work should be checked at diagnosis, day 30, day 60, and day 80 (just before the end of the 12-week treatment period) to confirm if the treatment can be stopped.

 

Administration: Oral tablets are given once daily and are dosed based on the cat’s weight, the type of FIP being treated, and the clinical response after treatment initiation. Injections are given subcutaneously (just under the skin) every 24 hours, ideally at the same time each day.

 

Side Effects: Appear to be unseen for the oral formulation. The primary side effect of GS injections which may cause pain at the injection site, which is temporary. Some cats may develop injection-site sores.
 


Need to calculate the right medication dosage for your cat? Use our free GS Tablet Dosing Calculator here.


Other Medications Prescribed Alongside GS That Avrio Can Help With:

(This is not an all-inclusive list) 
  • Prednisolone – available in tablets, liquid, and capsules to help with inflammation 
  • Gabapentin – available in tablets, liquid, and capsules to help calm your cat 
  • Mirataz® or Mirtazapine – transdermal product often prescribed for appetite stimulation 
  • Cerenia® or Maropitant – tablets or liquid formulations are available for nausea 
  • Doxycycline – liquid formulation available for bacterial infection 
  • Metronidazole – capsules and liquid formulations available to treat infections or diarrhea 
  • Denamarin® or Milk thistle with SAMe – tablets or liquid formulation available for liver support 
 
 

Helping Pets Live Happier And Healthier Lives.

Why Choose Avrio Pharmacy?

At Avrio Pharmacy, we are dedicated to advancing veterinary medicine through innovative compounding solutions. Our team of experienced pharmacists is committed to providing high-quality, customized medications that meet the unique needs of each patient. We understand the importance of compassionate care and work closely with veterinarians to find the best treatments to produce the best possible outcomes for your pet. 

If you have any questions about GS tablets or would like to discuss treatment options for a cat with feline infectious peritonitis, please don’t hesitate to contact us. Our knowledgeable staff is here to assist you and provide the support you need. 

Veterinarians! You can easily submit new prescriptions to our pharmacy team via phone, fax, or by using our free online prescribing platform for veterinarians at order.avriorx.com.

feline infectious peritonitis

Explore Our FAQs!

If your cat vomits within 1 hours of administering the pill(s), it is typically recommended to give another full dose. Always check with your veterinarian or care team member to discuss dosing questions. 

Oral dosing with GS will require a higher dose of the tablet to account for differences in the bioavailability of the tablet versus the injectable. 

There are many online pharmacies that sell GS tablets among other medications. Most of the pharmacies are located outside of the US and are not sourcing their active ingredients from FDA registered wholesalers. The FDA often warns about the risks from ordering from unknown sources.  At Avrio Pharmacy, we only source GS-441524 from FDA registered wholesalers and review a certificate of analysis (CoA) prior to dispensing to any patients.  

FIP is not contagious and therefore not necessary to separate your FIP kitty from other cats in the home.

A lot of cats develop diarrhea in the beginning of treatment. Using a probiotic, 100% pumpkin puree, B12 injections, or antibiotic like metronidazole may be several options that your veterinarian may recommend.  

You or your provider may reach our pharmacy team at 480-270-6700 Monday-Friday 8:30 am to 5:30 pm Arizona time and Saturday 9:00 am to 2:00 pm.  We have dedicated phone lines for both patients and providers to connect the most appropriate team (human compounding, veterinary medicine, retail pharmacy). We do close for major holidays, which may impact our phone hours.

You may also visit our pharmacy in-person Monday-Friday 8:00 am-6:00 pm and Saturday 9:00a-2:00p Arizona time to speak with a member of our team.

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