FIP is no longer a death sentence for cats. Here’s everything you need to know about it, including the latest treatment options.
What is FIP?
Feline infectious peritonitis (FIP) is a painful, previously untreatable disease that causes the immune system to overreact. It impacts a number of crucial organ systems, and has almost always been fatal. But over the past few years, thousands of cats have been cured of FIP with a newly-approved antiviral drug.
This article covers the causes and symptoms of FIP, the new FIP treatment available, and shares the story of cat Jynx’s full recovery.
What Causes FIP?
Much like the flu in humans, FIP is caused by a viral infection. The culprit is feline coronavirus, a common virus that infects 40%–80% of cats worldwide. AnimalBiome’s Chief Science Officer, Dr. Holly Ganz, describes feline coronavirus as “highly prevalent” in young cats. Like the flu, it usually causes only mild symptoms (if any at all), which disappear as young cats mature and their immune systems develop.
However, in rare cases, feline coronavirus results in the often-fatal disease FIP. Here, the mutated virus infects white blood cells, and triggers an intense immune system response. The resulting inflammation can wreak havoc in the intestines, brain, and gut.
What are the Symptoms of FIP?
FIP occurs in two forms: “dry” (non-effusive) and “wet” (effusive). The dry form of FIP may cause loss of appetite, weight loss, depression, and fever. The wet form of FIP causes fluid to accumulate in the abdomen or chest, which leads to a pot-bellied appearance and can interfere with a cat’s breathing. Both forms of FIP can cause neurological symptoms, like seizures or loss of coordination.
Up to this point, the lack of an FIP cure left pet parents and veterinarians in a heartbreaking position, with no option other than euthanasia.
How Does a Cat Become Infected with FIP?
Infection typically occurs when a healthy cat comes into oral contact with feces from an infected cat. Only about one-third of infected cats shed the virus in their feces, and most only do so for a few months. However, a small percentage may shed the virus throughout their lives.
Feline coronavirus can also remain dormant in the body for months or even years before mutating and causing FIP, even in healthy cats.
How Is FIP Diagnosed?
FIP is challenging to diagnose because its clinical signs overlap with other cat diseases. Blood tests may show abnormalities, but none are specific to FIP. X-rays can detect fluid in the abdomen, which can be analyzed for FIP, but it’s not always conclusive. FIP may also coexist with other conditions, further complicating the diagnosis.
Currently, the only definitive ways to diagnose FIP are via a post-mortem exam, or through examination of an infected tissue sample. Your veterinarian may take a biopsy from your cat for this reason.
Can a Cat with FIP Survive?
Feline infectious peritonitis used to be a death sentence for cats. Now for the first time, an antiviral drug has shown to be effective at treating FIP. Thousands of cats have been cured over the last three years.
One of those lucky cats is Jynx.
A happy, playful kitten, Jynx was adopted in November 2020 at 4.5 months old. But just a few months later, he suddenly became withdrawn and lethargic. Then he started hiding, wouldn’t eat, and his belly began to swell.
So Jynx was rushed to the ER in the middle of the pandemic. “Within 30 minutes they called to tell us how sick he was; he had days to live,” recalled Jynx’s distraught adopter, Lynn. He had all the symptoms of FIP — and as many cat parents will know, there is no cure.
However, Lynn’s veterinarian told her about an expensive black market drug with great success rates.
“It would cost $8k+, but we didn’t think twice,” said Lynn, who raced off to find a source. The most common form of the drug was an injectable version. While she was prepared to do anything to save Jynx, Lynn also knew weeks of daily injections would be painful and stressful for her beloved cat, who was already suffering.
Luckily, Lynn managed to source an oral version of the drug. She started Jynx on the medication right away. “Giving him pills was a challenge, as most cat parents know,” Lynn said. But Jynx responded quickly.
“Within days he had more energy. After 10 days Jynx knew the pills were helping, and we didn’t need to use a piller or restrain him,” shared Lynn. “He would gobble the pills up and would even wake us up on time for his pills!”
Within a few weeks, Jynx was back to his playful, goofy self.
Jynx finished his 84 days of medication at the end of June 2021, and made a full recovery from FIP. In the months after his treatment, he got to catch up on all the kitten play he’d missed. Now, two years later, Jynx is happier and healthier than ever before.
A Groundbreaking New Treatment For FIP
The drug Jynx took is GS-441524, which is a form of the antiviral drug remdesivir. While remdesivir needs to be injected, GS-441524 can be taken orally. Both remdesivir and GS-441524 are converted into the same active substance in the body.
Remdesivir made headlines during the pandemic when the FDA approved its use for emergency treatment of severe COVID-19. It is available for animal use in many countries including the UK and Australia, but until recently, neither remdesivir nor GS-441524 could be legally prescribed by veterinarians in the US.
So up to this point, desperate cat owners have turned to the black market. Many have been helped by FIP Warriors, an international network of cat parents, breeders, and rescuers, most of whom have firsthand experience with FIP treatment. They provide quick access to the drug, share information, and instruct owners on administering daily medication to their cats.
Recently, however, an injectable form of remdesivir called Veklury was finally made legally available to pet parents across the US.
The Future of FIP Treatment
Veklury is a newly approved treatment for adults and children with severe COVID-19. Luckily, it can also treat FIP, and veterinarians in the US are now able to prescribe Veklury to cats. This means pet parents no longer have to resort to the black market.
But we still have a long way to go to achieve affordable and painless treatment of FIP. For starters, Veklury still means months of daily injections for cats, and it’s very costly.
Professor Emeritus Niels C. Pedersen, of the UC Davis School of Veterinary Medicine, has been studying FIP since the 1960s. He was one of the first to test GS-441524 as an oral FIP treatment. “The goal should still be drugs specifically licensed for animals and available at a veterinary and not medical price,” says Dr. Pedersen.
This reality may not be far off. Promising new research in support of GS-441524 shows how safe and effective it is for treating FIP. These studies give us hope that an oral form of remdesivir will eventually become licensed and approved by the FDA for use in cats.
How Can I Protect My Cat Against FIP?
Even though treatment for FIP is now available, no pet parent wants their cat to go through a severe, painful illness. There is a licensed FIP vaccine available, but its ability to prevent FIP is uncertain, so it’s not currently recommended by the American Animal Hospital Association (AAHA).
Protecting against FIP is challenging, as it requires preventing the initial infection with feline coronavirus. However, there are a few ways to help your cat:
😌 Keep stress levels low. Stress can be a trigger for FIP. Avoid stressful situations including catteries and rescue organizations that house cats in crowded environments.
🐈 Keep your cat healthy. A healthy diet and up-to-date vaccinations for other viruses like feline leukemia and calicivirus can lower the risk of FIP.
🦠 Boost gut health. Gut health affects your cat’s overall health, and plays a key role in their immune response — so a healthy gut microbiome is vital. Luckily, there are scientifically developed cat microbiome supplements available.
🧼 Maintain good hygiene. Keep litter boxes clean and away from food and water dishes. If you’ve visited a cattery or shelter, wash your hands, shoes, and clothes before entering your home or interacting with your pets.
🩺 Be extra vigilant if your cat has FIP. If your cat has been infected and shows any signs of illness, even seemingly unrelated to FIP, they should see a veterinarian as soon as possible. “Their immune system is weaker and things like a basic head cold can be more serious in these guys,” advises AnimalBiome’s Director of Veterinary Relations, Dr. Tonya Cooksey.
For the first time there is hope for cats infected with FIP. Groundbreaking new treatments have helped Jynx, and thousands of other cats, make full recoveries. Many more success stories are sure to follow.
Because more than 70% of your cat’s immune cells live in their gut, a healthy gut microbiome is key to protect them from any illness. If you’d like to learn more about your cat’s gut health, try a KittyBiome Gut Health Test.