Cyprus is residence to 1 million or so free-roaming cats that wander its streets, parks, and even luxurious resorts. They’re about as quite a few as folks. So when a lethal cat outbreak started sweeping throughout the Mediterranean island this yr, the people shortly seen one thing was terribly flawed.
Stray and feral cats died by the 1000’s. Pet cats died, too. Their bellies turned swollen like bowling balls, a symptom attribute of the illness feline infectious peritonitis, or FIP, that’s virtually 100% deadly left untreated. FIP is brought on by a coronavirus that infects cats however not people. (It’s associated to however distinct from SARS-CoV-2.) The illness can fester in small, indoor outbreaks, however it had by no means raced throughout a complete island, leaving 1000’s of useless outside cats in its path. In early 2023, lab-confirmed FIP instances in Cyprus shot up 20-fold. The unusualness of this outbreak frightened cat house owners on the island and confounded veterinarians around the globe.
It appeared like one thing about FIP should have modified, however what? Had a brand new pressure appeared? Or, specialists questioned, may the outbreak have one thing to do with the unfold of COVID, additionally brought on by a coronavirus and in addition identified to contaminate cats?
Both approach, the pandemic got here with a silver lining for FIP: It made treating the cat illness rather a lot simpler. The 2 coronaviruses share sufficient similarities that COVID antivirals are additionally efficient in opposition to FIP—in reality, they’re downright miracle cures. “It’s like bringing these cats again from the useless,” says Gary Whittaker, a virologist at Cornell who research FIP.
The primary FIP treatment appeared a pair years earlier than the pandemic, however for a very long time cat house owners’ may solely purchase black-market variations on-line. The response to COVID supercharged analysis into antivirals in opposition to coronaviruses, increasing the arsenal of medication and making them extra extensively out there. So Cyprus was oddly ready for this new viral scourge. This summer season, the federal government started releasing leftover stockpiles of the COVID antiviral molnupiravir for cats with FIP. If this outbreak had occurred even a couple of years earlier, Cyprus would have needed to watch helplessly as its cats died one after the other.
In January, veterinarians on Cyprus started noticing an uncommon variety of FIP instances. Demetris Epaminondas, the vice chairman of the Pancyprian Veterinary Affiliation, advised me that his spouse, additionally a veterinarian, hadn’t seen any instances of FIP the yr earlier than. This yr, she’s seen greater than 50. The earliest instances clustered within the capital metropolis of Nicosia, however they quickly started radiating outward, reaching probably the most rural, distant areas of Cyprus final—as if a novel pathogen was spreading from an preliminary epicenter.
The feline coronavirus is a perplexing virus that strikes totally different cats in radically other ways. In most cats, it infects the intestine, inflicting solely non permanent diarrhea, if any signs in any respect. However in a small minority—maybe these already beneath stress or with a genetic predisposition—the virus mutates into a brand new and distinctive pressure contained in the cat, infecting white blood cells that journey all through the physique inflicting irritation. Notably, these mutated strains not often unfold to different cats. When the virus positive aspects the power to trigger extreme illness, it appears to lose the power to contaminate new hosts. It retains working smack into an evolutionary trade-off.
However in uncommon instances, the virus turns right into a “scorching pressure,” says Danielle Gunn-Moore, a feline drugs specialist on the College of Edinburgh. These strains have simply the correct mutations to sicken cats with FIP and unfold to new ones. Scientists intently documented one such outbreak in a shelter in Taiwan, the place the identical pressure of FIP appeared to kill eight cats. Gunn-Moore and her colleagues in Edinburgh—together with Charalampos Attipa, a vet initially from Cyprus who gathered a few of the preliminary outbreak knowledge—are actually sequencing viruses to see if a very scorching pressure has developed the power to unfold on an enormous scale. Piecing the genomes collectively has been technically difficult, she advised me, as a result of not like with COVID, researchers have few absolutely sequenced feline coronaviruses to make use of as reference. They hope to investigate the outcomes from about 100 samples quickly. An uncommon “scorching pressure”—maybe mixed with some genetic disposition in Cyprus’s cats—is the staff’s high speculation.
It didn’t escape their consideration, although, that this uncommon outbreak comes on the heels of an outbreak of one other coronavirus: SARS-CoV-2, after all. The staff questioned if the feline coronavirus may have recombined with SARS-CoV-2 to create a virulent new coronavirus, although the 2 are divergent sufficient that this situation can be uncommon. Or may SARS-CoV-2 be concerned however not directly? FIP reveals an uncommon sample the place earlier immunity from a vaccine can perversely make the illness even worse, Gunn-Moore advised me. (This has foiled FIP vaccines for cats, although the sample doesn’t present up with COVID vaccines for people.) COVID has probably contaminated a few of these cats lately, and he or she wonders if having had COVID may worsen FIP in an analogous approach—an surprising consequence of the worldwide pandemic.
Till fairly lately, vets had no option to deal with FIP. The turning level got here in 2018, when a researcher at UC Davis examined a brand new drug chemically much like the antiviral drug remdesivir in 10 cats with FIP. All 10 had been cured. This was extraordinary. Information of the miracle treatment started spreading by phrase of mouth, however as a result of the corporate that patented the drug refused to license it, Chinese language producers started making very profitable black-market variations. Remdesivir, which additionally works in opposition to FIP, has since turn out to be out there via numerous means too.
In late 2020, as new COVID antivirals equivalent to molnupiravir started producing buzz, Chinese language producers as soon as once more noticed the potential for FIP. An organization started promoting unlicensed molnupiravir to abroad cat house owners, touting an unpublished research through which 286 cats had been all absolutely cured. Who is aware of how a lot inventory to absorb this, however remarkably, peer-reviewed analysis has since validated the effectiveness of the drug. In 5 years time, FIP has gone from the “worst prognosis you could possibly get” for cats to a illness absolutely curable with not one however three totally different medication, says Nicole Jacque, a cat-rescue volunteer who has helped conduct analysis on molnupiravir. The curiosity that the pandemic spurred in coronavirus antivirals has been a boon for FIP. (Vets advised me that Paxlovid might be a promising antiviral for FIP too, although nobody appears to have examined it but.)
When the FIP outbreak hit Cyprus, folks there additionally started shopping for black-market medication. The fee is extremely excessive, working into 1000’s of U.S. {dollars} per cat relying on the precise drug. And there’s no assure that the merchandise actually include the drug on the purity and the doses claimed. “We can not depend on the black market,” Epaminondas says. Vets in Cyprus started asking the federal government for assist earlier this yr. By then, molnupiravir had been falling out of favor globally as a human drug, as Paxlovid had proved simpler. The Cypriot authorities had loads of molnupiravir left over, and it agreed to launch the primary doses to veterinarians this summer season.
Though molnupiravir can actually deal with FIP, it is probably not the “greatest” drug for it. In lab research, it appears poisonous at decrease quantities than the opposite choices, so it might be simpler to by accident overdose. And since molnupiravir works by inducing a lot of mutations within the virus—to the purpose the place it ought to cease working—specialists have questioned if it may velocity up the emergence of latest variants, a concern that beforehand dogged its human use.
However molnupiravir has massive sensible benefits too: It’s the most cost-effective of the FIP medication. And within the U.S., it’s the almost certainly to be available, says Drew Weigner, a former president of the EveryCat Well being Basis, which has funded a number of FIP drug research beneath his tenure. The drug is at the moment licensed for emergency use for COVID, but when it’s formally accredited, vets may additionally prescribe it off-label to cats. After which America, too, may lastly have a authorized drug to deal with FIP—in case the outbreak spreads globally, and even when not, for the numerous cats that also routinely get FIP yearly.
