In recent months, thousands of cats in Cyprus have succumbed to a new form of a coronavirus that is non-threatening to humans. The virus has now been detected for the first time in the United Kingdom.
According to a group of researchers from the University of Edinburgh under the direction of virologist Christine Tait-Burkard, they discovered the feline coronavirus variant known as F-CoV-23 in a British cat. The animal had arrived on the island from Cyprus, where the importation of stray cats from the Mediterranean island is widespread in England.
In their study, which has been published only as a preprint and has not yet undergone peer review by independent colleagues, the team delved into the question of the outbreak in Cyprus. Typically, the virus does not spread so easily. However, in estimates, at least 8,000 animals have perished on the island, where hundreds of thousands of cats live as stray animals. The actual number of casualties, though, could be much higher.
In the examination of the genome of the feline coronavirus responsible for the outbreak, the team has now identified a combination of two different viruses. The spike protein, accountable for binding to the host cell, did not originate from the feline virus but rather from a coronavirus variant commonly found in dogs.
This combination appears to lead to an increased incidence of the dreaded Feline Infectious Peritonitis (FIP) in infected cats. The animals do not succumb to the virus itself, but rather to a form of peritonitis or other diffuse symptoms. FIP is prevalent worldwide and typically results in a fatal outcome for cats. It has been known for some time that mutated feline coronaviruses can cause this disease, but these viruses typically do not spread so readily. Therefore, the severe outbreak observed in Cyprus since January 2023 has been puzzling.
Consequences for England’s Cats Unclear
The responsible variant, F-CoV-23, is likely transmitted through the feces of animals and via oral routes. Currently, there is no evidence suggesting that the virus can infect humans, dogs, or other pets.
The impact on domestic cats in the UK is challenging to estimate. “I must be clear that it is very hard to predict if the virus will spread well here or in other countries,” writes Amanda Warr, a researcher involved in the study. Cyprus has a high population of cats, which promotes transmission. However, the animals there seem to have a certain immunity to precursor viruses, which may not be the case for cats in the UK.
The scientists, so far, do not see any reason for British cat owners to deny their pets access to the outdoors and confine them indoors. However, if the animals appear depressed, have a fever, experience seizures, or exhibit a swollen abdomen, a veterinarian should be consulted.
The research team also does not currently observe any connection with COVID-19, the variant responsible for the human pandemic. Similar virus combinations in cats have been observed before.
In Cyprus, even COVID-19 medications developed for humans are allowed to be administered to affected animals in an effort to combat cat mortality. In August, a government spokesperson stated that preparations from stocks no longer in use are utilized for this purpose. According to animal welfare organizations, these include the antiviral medications Remdesivir and Molnupiravir.