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FIP is Killing Cats...a Cure Exists...So Why isn't it Available?

fip, killing cats, cats, stray cat, cat overpopulation

Bella the cat was only 8 months old when she became exhausted and her stomach looked extremely bloated. Her guardian, Andrea — a friend of a 600 Million Dogs team member — feared the worst.

These were clear signs of Feline Infectious Peritonitis (FIP), a disease tied to a specific strain of cat coronavirus.

FIP was previously considered to be fatal for cats. However, over the last few years, certain drugs have been found to be effective in treating FIP and giving cats the chance to live. 

Yet these drugs remain illegal or inaccessible across much of the world and the U.S. 

Thankfully, Bella was able to access FIP treatment since her guardian lives in Asia. Bella was much better within just a week of being given an FIP drug that is currently unavailable in the U.S.

Across the U.S., cats with FIP suffer horrendously from the vicious virus that ravages their bodies.

So, what is FIP, and why is it so hard to access treatment? 

What is FIP?

FIP is a viral disease in cats caused by certain strains of a virus called feline coronavirus. Feline coronavirus infects about 40%-80% of cats worldwide, most commonly in cats under 2 years old. 

In early 2023, thousands of cats mysteriously died in Cyprus, famously known as the "island of cats." The situation rapidly worsened, capturing the attention of international media. The cause was found to be FIP.

Most strains of feline coronavirus are relatively harmless, and it tends to go away as the cats get older and develop immunity. 

However, in 5%-10% of cases, the virus mutates into a much more serious disease: feline infectious peritonitis.  

Symptoms of FIP

The symptoms of FIP can be hard to spot because they're similar to other illnesses. However, there are specific signs to watch for:

Fever that doesn’t go away: If your cat has a fever that keeps coming back, even after medication, it could be a sign of FIP.

Lack of appetite and weight loss: Cats with FIP may stop eating as much as they used to, leading to weight loss.

Lethargy or depression: Cats might become less playful or seem tired all the time.

Swelling in the abdomen or chest: This is a sign of fluid build-up, which is common in FIP.

Breathing difficulties: If the disease affects the chest, your cat might have trouble breathing.

Jaundice: This is a yellowing of the skin and eyes and is a serious sign that the liver may be affected.

Eye problems: Some cats might have inflamed eyes or changes in eye color.

Neurological symptoms: In advanced cases, cats might have trouble walking, seem disoriented, or have seizures.

Wet vs. Dry FIP

There are two types of FIP: wet and dry.


The "wet" form of FIP is named because it leads to the accumulation of fluid in the body. This fluid typically builds up in the belly or chest, causing the abdomen to swell or leading to breathing difficulties.

In the most severe cases of wet FIP, cats may have to undergo thoracentesis. This involves inserting a needle into the cat's abdomen to remove the excess fluid.

Cats with wet FIP might seem to have a bloated stomach and may struggle to breathe normally. This form of FIP can worsen quickly and is often more noticeable due to these symptoms.


On the other hand, "dry" FIP is more subtle and sneaky. It doesn't cause fluid buildup; instead, it leads to inflammation in various organs like the kidneys, liver, eyes, or brain. The symptoms of dry FIP can vary widely depending on which organs are affected, and they tend to develop more slowly. A cat with dry FIP might lose weight, seem tired, have a fever, or show other less obvious signs of being sick.

Could GS-441524 be the Cure?

When Robin Kintz’s two kittens, Fiona and Henry, came down with FIP, she scrambled to find solutions. She started hearing about a black-market drug from China, GS-441524. After doing thorough research, she found credible sources from UC Davis indicating that the drug could be effective. 

Kintz, with no other solutions in sight, transferred thousands of dollars to the source in China. She received the vials and began injecting her cats with the drug. Henry lived for almost another year, and Fiona fully recovered from the virus. 

UC Davis found that using GS-441524 didn’t just prolong a cat’s life, but was able to cure the cat of the disease in many cases. 31 companion animal cats who had naturally gotten the virus were enrolled in the study, and 25 of them ultimately survived, “an unheard-of recovery rate,” according to Medium. 

According to Drew Weigner, a veterinarian and the president of the Winn Feline Foundation, “It really was a game changer .... Three years ago, we told patients, ‘Your cat is going to die.’ Now we can tell them something else.”

Despite promising results, the drug still remains available only on the black market in the U.S. A 12-week regimen of the drug can cost over $10,000.

The good news is, GS-441524 has become available for veterinary use in the UK, Australia, and the Netherlands, but it needs to be available everywhere.

fip, killing cats, cats, stray cat, cat overpopulation

So why is the drug inaccessible in the U.S. and elsewhere?

Gilead Sciences is the developer behind GS-441524. So far, Gilead has refused to license GS-441524 for use in cats. 

Gilead’s focus had been on a similar drug called remdesivir. 

According to an article published by Medium, “Gilead worried that the cat research could impede the approval process for remdesivir. Because GS-441524 and remdesivir are so similar, any adverse effects uncovered in cats might have to be reported and investigated to guarantee remdesivir’s safety in humans.”

Susan Gingrich’s kitten, Bria, died of FIP in 2005 when he was just 9 months old. She founded the Bria Fund in his honor, dedicated to supporting FIP research. In 2019, Gingrich wrote a letter to Gilead and U.S. government officials in an effort to convince the company to allow use of the drug for animals. She never received a response.


As mentioned above, the treatment for FIP is now legal in the UK, Australia, and the Netherlands. Neils Pedersen, the scientist at UC Davis who pioneered the studies, credits the success to advocacy by veterinarians. 

How can I help cats with FIP?

The cure to this devastating disease exists. We are calling on Gilead Sciences to do the right thing and license the drug for use in cats! 

Please sign our petition to send a message to the CEO of Gilead, Daniel O’Day. If you are unable to access the petition or would like to send a personal message, the email address is

Feel free to copy/paste the message below or write your own message.

Petition Text:

Dear Daniel O'Day and Gilead,

Please authorize the use of GS-441524 for the treatment of Feline Infectious Peritonitis in the U.S. and worldwide, immediately. This would save the lives of many cats and prevent many cat guardians from suffering the heartbreak of losing their beloved companion animals to this disease.

FIP is a devastating disease that affects cats worldwide, almost always leading to death once identifiable symptoms appear. The discovery of GS-441524 and its effectiveness in clinical trials has brought hope to many. However, the lack of licensing for veterinary use has left a gaping hole in the resources available to fight this disease.

Gilead Sciences has been at the forefront of groundbreaking medical advancements, including the development of GS-441524. While we understand that the focus has been on developing treatments for human disease such as COVID-19, we strongly urge you to consider the vital impact that licensing GS-441524 for veterinary use could have on cats and their human guardians.

The current situation has driven desperate cat guardians to seek this medication through unregulated channels, risking counterfeit or ineffective treatments. This not only endangers the health of cats but also places a huge emotional and financial burden on their guardians.

We believe that Gilead Sciences has the unique opportunity to make a profound difference in the lives of countless cats and their families by making GS-441524 legally and readily available for veterinary use worldwide.

Please authorize the use of GS-441524 for FIP treatment. By doing so, you would be reinforcing Gilead Sciences' commitment to improving lives, regardless of the species.


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