That's how to do it: If humans have COVID-19, dogs had better cuddle with their stuffed animals. Researchers from Utrecht in the Netherlands took nasal swabs and blood samples from 48 cats and 54 dogs in 2021 whose owners had contracted COVID-19 in the last 200 days. Lo and behold, they found the virus in 17.4% of cases. Of the animals, 4.2% also showed symptoms.

About a quarter of the animals that had been infected were also sick. Although the course of the illness was mild in most of the animals, three were considered to be severe. Nevertheless, medical experts are not very concerned. They say pets do not play an important role in the pandemic. The biggest risk is human-to-human transmission.

The fact that cats can become infected with coronaviruses has been known since March 2020. At that time, the Veterinary Research Institute in Harbin, China, had shown for the first time that the novel coronavirus can replicate in cats. The house tigers can also pass on the virus to other felines, but not very easily, said veterinarian Hualan Chen at the time.

But cat owners shouldn't panic. Felines quickly form antibodies to the virus, so they aren't contagious for very long. Anyone who is acutely ill with COVID-19 should temporarily restrict outdoor access for domestic cats. Healthy people should wash their hands thoroughly after petting strange animals.

Should this pet pig keep a safe distance from the dog when walking in Rome? That question may now also have to be reassessed. Pigs hardly come into question as carriers of the coronavirus, the Harbin veterinarians argued in 2020. But at that time they had also cleared dogs of suspicion. Does that still apply?

Nadia, a four-year-old Malaysian tiger, was one of the first big cats to be detected with the virus in 2020 — at a New York zoo. "It is, to our knowledge, the first time a wild animal has contracted COVID-19 from a human," the zoo's chief veterinarian told National Geographic magazine.

In early December 2021, two hippos at Antwerp Zoo in Belgium tested positive for coronavirus. Both animals, mother Hermien and daughter Imani, had a cold. Otherwise, they were doing well. The zoo had to close temporarily and quarantine the hippos.

It is thought that the virus originated in the wild. So far, bats are considered the most likely first carriers of SARS-CoV-2. However, veterinarians assume there must have been another species as an intermediate host between them and humans in Wuhan, China, in December 2019. Only which species this could be is unclear.

This racoon dog is a known carrier of the SARS viruses. German virologist Christian Drosten spoke about the species being a potential virus carrier. "Racoon dogs are trapped on a large scale in China or bred on farms for their fur," he said. For Drosten, the racoon dog is clearly the prime suspect.

Pangolins are also under suspicion for transmitting the virus. Researchers from Hong Kong, China and Australia have detected a virus in a Malaysian Pangolin that shows stunning similarities to SARS-CoV-2.

Hualan Chen also experimented with ferrets. The result: SARS-CoV-2 can multiply in the scratchy martens in the same way as in cats. Transmission between animals occurs as droplet infections. At the end of 2020, tens of thousands of martens had to be killed in various fur farms worldwide because the animals had become infected with SARS-CoV-2.

Experts have given the all-clear for people who handle poultry, such as this trader in Wuhan, China, where scientists believe the first case of the virus emerged in 2019. Humans have nothing to worry about, as chickens are practically immune to the SARS-CoV-2 virus, as are ducks and other bird species.