The new coronavirus, ‘feline coronavirus 23’ or FCov-23, is not dangerous to humans because it cannot infect human cells. But it can make cats seriously ill, as has been known since the virus emerged in Cyprus in January this year grabbed around – although no one is really worried about a pandemic in cat country.
The animals contract cat corona or ‘fip’ (‘feline infectious peritonitis’), with fever, a swollen abdomen and hair loss. Without intervention, death will eventually follow. Fortunately, Fip can be treated with virus inhibitors, including the remdesivir used in humans.
Fcov-23 is a mixture of cat and dog corona, British and Greek scientists write in an research article that is now available as a pre-publication on the internet. “What is striking is that the cat virus has picked up almost the entire spike protein from the dog virus,” explains professor of coronavirology Eric Snijder (LUMC) when asked.
Imported cat
For the time being, there is only one known case outside Cyprus: a imported cat from Cyprus in Great Britain. But vigilance is required, says veterinary virologist Herman Egberink (Utrecht University). “There seems to me to be a chance that you can also get infected cats here, through foundations that import cats, or people who bring a cat from a southern country.”
Both virologists expect that it will probably remain isolated cases. FCov-23 does not seem to be very contagious yet, and “cats cannot fly,” notes Snijder, referring to the bird flu that spread through bird migration. Moreover, the disease is currently at a low level in Cyprus itself.
Through feces and paws
Cat corona is usually a mild intestinal disease that spreads through feces and paws and does not make cats very ill. But every now and then the harmless virus undergoes a mutation, which can cause the cat to get fip, the serious form of feline corona.
However, so far the fip variant of the virus has not been able to infect other cats. Now the virus apparently has that ability, thanks to the spike proteins of the canine coronavirus. “We know that recombination is important in coronaviruses and can have unexpected results,” Snijder notes. “But this is yet another warning.”
Snijder also believes that the chance that such a recombination (exchange of genetic material) will take place with a human coronavirus is small, if only because cat corona is on a different branch of the virus family tree than SARS-COV-2, the pandemic coronavirus.
On the other hand, cat corona is related to the human corona cold viruses called 229E and NL63. “Recombination is a sliding scale. The chance is never zero,” says Snijder.
