Cyprus is home to 1 million or so free-roaming cats that wander its streets, parks, and even luxurious resorts. They are about as quite a few as folks. So when a lethal cat outbreak started sweeping throughout the Mediterranean island this yr, the people rapidly seen one thing was terribly fallacious.
Stray and feral cats died by the hundreds. Pet cats died, too. Their bellies grew to become swollen like bowling balls, a symptom attribute of the illness feline infectious peritonitis, or FIP, that’s almost one hundred pc deadly left untreated. FIP is brought on by a coronavirus that infects cats however not people. (It is said to however distinct from SARS-CoV-2.) The illness can fester in small, indoor outbreaks, nevertheless it had by no means raced throughout a complete island, leaving hundreds of useless out of doors cats in its path. In early 2023, lab-confirmed FIP instances in Cyprus shot up 20-fold. The unusualness of this outbreak frightened cat homeowners on the island and confounded veterinarians all over the world.
It appeared like one thing about FIP will need to 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 likewise recognized to contaminate cats?
Either approach, the pandemic got here with a silver lining for FIP: It made treating the cat illness quite a bit simpler. The two coronaviruses share sufficient similarities that COVID antivirals are additionally efficient towards FIP—in actual fact, they’re downright miracle cures. “It’s like bringing these cats back from the dead,” says Gary Whittaker, a virologist at Cornell who research FIP.
The first FIP remedy appeared a pair years earlier than the pandemic, however for a very long time cat homeowners’ may solely purchase black-market variations on-line. The response to COVID supercharged analysis into antivirals towards coronaviruses, increasing the arsenal of medicine and making them extra broadly available. 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 vp of the Pancyprian Veterinary Association, 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 essentially 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 completely different cats in radically alternative ways. In most cats, it infects the intestine, inflicting solely momentary diarrhea, if any signs in any respect. But 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 hardly ever unfold to different cats. When the virus positive factors 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.
But in uncommon instances, the virus turns right into a “hot strain,” says Danielle Gunn-Moore, a feline drugs specialist on the University of Edinburgh. These strains have simply the precise mutations to sicken cats with FIP and unfold to new ones. Scientists carefully 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 number of the preliminary outbreak information—at the moment are 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 “hot strain”—maybe mixed with some genetic disposition in Cyprus’s cats—is the crew’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 crew 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 state of affairs could be uncommon. Or would possibly 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 she or he wonders if having had COVID would possibly worsen FIP in an identical approach—an surprising consequence of the worldwide pandemic.
Until fairly lately, vets had no strategy 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 unparalleled. News of the miracle remedy started spreading by phrase of mouth, however as a result of the corporate that patented the drug refused to license it, Chinese producers started making very profitable black-market variations. Remdesivir, which additionally works towards FIP, has since turn out to be available by numerous means too.
In late 2020, as new COVID antivirals comparable to molnupiravir started producing buzz, Chinese producers as soon as once more noticed the potential for FIP. An organization started promoting unlicensed molnupiravir to abroad cat homeowners, touting an unpublished research during 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 diagnosis you could get” for cats to a illness absolutely curable with not one however three completely different medicine, 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 may very well 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 medicine. The cost is extremely excessive, working into hundreds of U.S. {dollars} per cat relying on the precise drug. And there’s no guarantee that the merchandise actually include the drug on the purity and the doses claimed. “We cannot rely 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 more practical. The Cypriot authorities had loads of molnupiravir left over, and it agreed to launch the primary doses to veterinarians this summer season.
Although molnupiravir can definitely deal with FIP, it might not be the “best” drug for it. In lab research, it appears poisonous at decrease quantities than the opposite choices, so it may very well be simpler to by accident overdose. And as a result of molnupiravir works by inducing plenty of mutations within the virus—to the purpose the place it ought to cease working—specialists have questioned if it may pace up the emergence of recent variants, a priority that beforehand dogged its human use.
But molnupiravir has large practical benefits too: It is the most cost effective of the FIP medicine. And within the U.S., it’s the almost certainly to be readily available, says Drew Weigner, a former president of the EveryCat Health Foundation, 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 authorized, vets may additionally prescribe it off-label to cats. And then America, too, would possibly lastly have a authorized drug to deal with FIP—in case the outbreak spreads globally, and even when not, for the various cats that also routinely get FIP yearly.
