On May 8, 2020, the Institute for Agricultural Food Research and Technology (IRTA) reported the case of the first cat infected with SARS-CoV-2 in Spain. It was a 4-year-old cat named Negrito who lived with a COVID-19 affected family and who had a death.
Simultaneously with these facts, the animal showed severe breathing difficulties and was taken to a veterinary clinic in Badalona (Barcelona), where it was diagnosed with hypertrophic cardiomyopathy. Due to an incurable condition, the hospital opted for humanitarian euthanasia.
Autopsy performed at the IRTA̵
The RT-PCR test confirmed that the animal had been infected with SARS-CoV-2, but with a very low and residual viral load.
So far, there have been only a few cases of SARS-CoV-2 infections in cats worldwide. Therefore, researchers deepened the case study and recently published it in the journal Procedure of the National Academy of Sciences (PNAS).
They ran serological tests on the cat Negrito and another cat who also lived in the same house, whiskey that showed no signs of illness. The tests carried out by the AIDS Research Institute (IrsiCaixa) show that the two cats had developed antibodies against SARS-CoV-2.
“In both cases, we detected neutralizing antibodies, ie they can bind to the virus and block it,” explains Julià Blanco, IGTP researcher at IrsiCaixa.
He continues, “This is important because it shows us that cats’ immune systems can handle SARS-CoV-2 and protect them from developing symptoms in these specific cases.”
Experimental studies currently in progress show that cats can not only become infected with SARS-CoV-2, but can spread it to other cats nearby, but with no clinical signs.
However, the researchers’ first suspicions were that both Negrito and whiskey had been infected by their owners because they had no contact with other cats.
To verify this, the team analyzed the genetic sequence of the virus that Negrito had and found that “it bears a 99.9% similarity to the deceased owner’s virus, suggesting the cat came directly from family members infected, “explains Marc Noguera-Julián, researcher at IrsiCaixa.
Given the number of people infected worldwide and the few reported cases of animals, experts continue to state that “Pets play a negligible role in the epidemiology of SARS-CoV-2 and cats in particular become very residue-infected and there is no evidence that this is a case of reverse zoonosis, in which cats are the secondary victims without the virus causing any health problems, “explains Júlia Vergara-Alert, researcher at IRTA-CReSA.
So far only one episode has been reported in the Netherlands in which a farmer was infected by mink. This would be the first known potential case of COVID-19 zoonosis.
IRTA and the Council of Veterinary Associations of Catalonia, in cooperation with the Veterinary Clinic of the Universitat Autònoma de Barcelona, are investigating whether pets can be infected with SARS-CoV-2
Following the Negrito case, the IRTA-CReSA coronavirus research team started a study in May, in coordination with the Council of Veterinary Colleges of Catalonia and the Veterinary Clinic of the Universitat Autònoma de Barcelona, to assess how often cats, dogs and ferrets have lived with SARS-CoV-2 infected from people in a family setting.
The study is carried out with the voluntary participation of veterinary clinics and hospitals in Catalonia and consists of taking samples of oropharyngeal and rectal swabs, as well as animal serum.
We want to check whether the case of Negrito and Whiskey was on time or if it is repeated in other cases. In this way, we get more scientific information on how and to what extent the most common pets can be infected with SARS-CoV-2. “
Joaquim Segalés, IRTA-CReSA Researcher and Professor, Faculty of Veterinary Medicine, The Autonomous University of Barcelona
The professor also notes: “So far it has been known that there have been some cases worldwide of cats and dogs infected by their owners, but these animals have not suffered any serious illness and there is no evidence that the virus is transmitted to their owners” .
The Autonomous University of Barcelona