Medication to treat deadly feline infectious peritonitis may be more accessible soon

Is the wait by U.S. cat lovers and veterinarians for legal access to medication for feline infectious peritonitis (FIP) — a complex, devastating and nearly always fatal disease of cats — nearly over?

For the past few years, an experimental antiviral treatment — GS-441524 — has only been available in the United States via the black market. It’s a nucleoside analogue, which works by preventing the virus from replicating, and it was found to be effective in a study funded by EveryCat Health Foundation (EHF) at the University of California, Davis, School of Veterinary Medicine. For owners able to acquire it, the treatment saves many cats’ lives.

The hangup? Because it’s a black-market product, veterinarians cannot prescribe or recommend it.

But the word on the street (aka FIP support groups on social media) is that a compounded form of the medication will become available as early as June.

The medication will not be approved by the Food and Drug Administration because the FDA does not verify the safety or effectiveness of compounded drugs. But FDA rules would make the treatment acceptable for veterinary use. According to the FDA’s website, when no medically appropriate drug is approved or conditionally approved to treat nonfood-producing animals, veterinarians may access unapproved drugs to treat their patients (details available at fda.gov).

I spoke to Vicki Thayer, DVM, DABVP, the director emeritus at EHF, about how availability could change the FIP treatment landscape.

Medication for FIP has been available for the last couple of years in other countries, including Australia, Canada and the United Kingdom, with good results. Many U.S. veterinarians have been reluctant to treat cats with FIP because of legal concerns, but if the drug becomes legally available here, that should change, Thayer said.

She added that there may be a bit of a learning curve: “Probably they’re going to have to learn a lot of information in regard to other care that goes along with treating these cases,” Thayer said, “because cats do still need a lot of supportive care.”

Cat lovers who have purchased FIP drugs on the black market know that the medication their cats need to survive is expensive, and Thayer said that’s unlikely to change immediately. But if and when an FDA-approved medication becomes available, pet health insurance should cover the treatment for policy holders.

It’s likely, too, that other antivirals will be developed, which could help to bring costs down.

“We need different ones because we want to try and prevent resistance of the virus to therapeutics,” Thayer said.

FIP was first recognized in the 1960s by Jean Holzworth, DVM, at Boston’s Angell Animal Medical Center. But because of its complexity, it was difficult to find an effective treatment. In the past de[1]cade, though, breakthroughs in the development of antivirals for humans led to the ability to utilize those medications for cats and other species.

The arrival of COVID-19 may have both helped and hindered development of an FIP treatment for cats. To some degree, it helped to bring recognition to the benefits of antivirals, Thayer said, but with research and funding targeted toward humans, less was available for studying the effects in animals.

But now feline research projects at veterinary colleges may be back on track, and Thayer expects to see more breakthroughs in the near future: “Within the next few years, there are going to be a lot more available treatments to choose from.”

For now, she said, the important thing is still to have a good support team, such as those developed through social media groups dedicated to fighting the disease. “I think that’s one (good) thing that has come” from the FIP treatment struggle over the years, she said: “just the support, learning from each other, how to treat these cats and tips on what to look for.”

Find out more about FIP medication and management at icatcare.org/app/uploads/2024/03/FIP-update-Feb-2024.pdf, and check Facebook for FIP support groups such as FIP Felines: Hope and Support, FIP Global Cats, FIP Warriors and Help for FIP.

Do you have a pet question? Send it to askpetconnection@gmail.com or visit Facebook.com/DrMartyBecker. Pet Connection is produced by veterinarian Dr. Marty Becker, journalist Kim Campbell Thornton, and dog trainer/behavior consultant Mikkel Becker. ©2024 Andrews McMeel Syndication

This article originally appeared on South Bend Tribune: Pet Connection: Treating infectious peritonitis in felines