A new study implies that cats’ immune system can fight Sars-Cov-2
The Institute of Agrifood Research and Technology (IRTA) recorded the case of the first cat infected with SARS-CoV-2 in Spain, on 8 May 2020. The 4-year-old cat named Negrito, lived with a family affected by COVID-19, with one case of death.
Due to this, the cat had a case of severe respiratory complications and was taken to a veterinary hospital in Badalona (Barcelona). At the veterinary hospital, Negrito was diagnosed with hypertrophic cardiomyopathy.
This condition moved the hospital to do a humanitarian euthanasia.
The necropsy, carried out at the High Biosafety Level Laboratories of the Animal Health Research Center (CReSA) at IRTA, verified that Negrito had issue of feline hypertrophic cardiomyopathy and no other lesions or symptoms similar to a coronavirus infection was found.
The RT-PCR test verified that the Negrito was infected with SARS-CoV-2, but with an incredibly low and residual viral load.
At the moment, there are only a few cases of feline SARS-CoV-2 infection worldwide, and due to this, researchers have gone further with the case study and published it in the journal Proceedings of the National Academy of Sciences (PNAS).
They conducted serological tests on the Negrito and another cat that lived in the same home, Whisky. Prior to the serological tests, Whisky did not show any signs of disease. The tests, conducted by the AIDS Research Institute (IrsiCaixa), revealed that the two cats had built antibodies against SARS-CoV-2.
“In both cases we have detected neutralizing antibodies, in other words, they have the ability to bind to the virus and block it,” says Julià Blanco, IGTP researcher at IrsiCaixa.
“this is important because it shows us that the immune system of cats can deal with SARS-CoV-2 and, in these specific cases, protect them from developing symptoms”. He continued.
Research shows that cats can infect other cats with Sars-Cov-2. But since the cats had not had contacts with other cats , they must have been infected by their owners.
To confirm this theory, the team examined the genetic sequence of the virus that Negrito had and found that “it has a 99.9% similarity to the virus of the owner who died, this suggests that the cat became directly infected from family members”, says Marc Noguera-Julián, researcher at IrsiCaixa.
The researchers are of the opinion that “pets play a negligible role in the epidemiology of SARS-CoV-2 and, in particular, cats become very residually infected and there is no evidence of transmission of the virus to humans. This is a case of reverse zoonosis, in which cats are the side victims without the virus causing them health problems”, states Júlia Vergara-Alert, researcher at IRTA-CReSA.