Are pigs safer than dogs

These farm animals and pets can become infected with the new coronavirus

A tigress in New York's Bronx Zoo, two dogs and cats in Hong Kong and Liège, Belgium - there have recently been individual reports that animals have also been infected with the new corona virus.

Cats can become infected with coronavirus in humans

With regard to the question of whether the virus can also spread back to humans from infected pets, scientists have now largely given the all-clear. They consider the risk of infection or spread of the pathogen from cats or dogs to humans to be relatively low:

  • According to previous knowledge, dogs are not susceptible to the new type of coronavirus SARSCoV-2 and can therefore not transmit the virus.
  • Studies have shown that cats can be infected experimentally, shedding the virus, and infecting other cats. Transmission from cats to humans is considered unlikely.

However, researchers at the Friedrich Löffler Institute advise:

Animal disease research on a lonely island in the Baltic Sea

On the remote island of Riems in the Baltic Sea, people have literally had the epidemic for over 100 years. That is why the small island in the Greifswalder Bodden is also a restricted area. The Friedrich-Löffler-Institut, founded in 1910, is shielded behind fences and barbed wire.

In its high-security laboratories, over 100 scientists experiment with dangerous viruses and other pathogens: foot-and-mouth disease, swine fever, "mad cow disease", BSE, bird flu - everything that can harm farm animals has already been scrutinized at Riems. And now the novel coronavirus.

Pigs are a "treasure trove" for pathogens.

Among other things, 20 chickens and 12 pigs were tested there for a possible infection with the SARS coronavirus-2. In particular, the lungs, liver, brain and other organs of the animals were examined more closely. Pigs in particular are considered to be a kind of “treasure trove” for pathogens. That is why they are particularly exciting for the researchers: pigs can become infected with a whole range of viruses. Among other things, also with influenza viruses (i.e. flu viruses) from very different areas. Whether the viruses come from humans or from birds or from wherever.

Beluga whales can also become infected with coronaviruses

Corona viruses have always been part of the mix of pathogens in pigs. But that is not what is currently causing a stir, emphasizes the biologist Elke Reinking. There are a number of corona viruses. Almost every animal species has its own coronavirus, even the beluga whale, for example! Coronaviruses can also cause epidemic diarrhea in pigs. But, according to biologist Elke Reinking, that has nothing to do with the SARS corona-2 virus. It is a family, but the viruses are very different.

Viruses use the same opening code in pigs, humans, cats and ferrets

But there is something else that makes pigs so special - and thus apparently also, like humans, particularly susceptible to the new pathogen: The entrance door through which the virus tries to penetrate the body cell - it has the same opening code in pigs and humans.

According to current knowledge, five amino acids, which seem to be the center to which this virus then docks, are important. And these five amino acids are the same in humans, pigs, cats and ferrets. It was therefore assumed that the pig should actually also be infectable with the SARS Corona-2 virus.

Pigs and chickens not susceptible to new coronavirus

But, says institute director Thomas Mettenleiter:

In the case of chickens, however, the virus definitely does not have a valid ticket to infect cells. The poultry only has two of the five important amino acids that the pathogen presumably needs to dock. Therefore, the corona defense in chickens can be explained relatively easily.

But why does the new pathogen not stand a chance in pigs either, although it initially looked as if this docking point looked like it did in humans? The biologist Elke Reinking has an assumption:

There is still no knowledge about horses and cows

The virus defense of pigs therefore still poses a number of puzzles to the researchers. So far, however, everything indicates that they are just as unaffected by the new pathogen as chickens. It is still unclear whether this also applies to horses and cattle, for example: relatively little is known about the receptors, the inlet port where a virus docks on the cells of its host animal.

Nevertheless: Corona experiments with horses have so far been taboo at the Friedrich Löffler Institute. And will stay that way, risk of epidemics or not. Biologist Elke Reinking is absolutely certain:

Flying foxes and ferrets susceptible to coronavirus

In addition to chickens and pigs, the scientists on the island of Riems also experimentally infected ferrets and flying foxes with the new corona virus. Flying foxes belong to the group of bats. That is why the researchers look very closely here, too, explains institute director Thomas Mettenleiter:

The research institute on the island of Riems is one of the few laboratories in Germany that are so elaborately secured that they can carry out such dangerous tests. Even if the disease researchers themselves are not developing anti-corona drugs and vaccines here - their studies could further accelerate research on this and help to protect many people from the new virus.

Zoonoses are infectious diseases that can be transmitted from person to animal and from animal to person. In the case of the novel coronavirus SARS-Cov-2, isolated transmissions from animals to humans have been detected. But there are also cases in which the new corona virus was probably transmitted from humans to cats or even tigers.

Most recently, a mutated form of the SARS-CoV-2 virus has spread in numerous mink farms in Denmark. This mutation has spread to humans in isolated cases, which is why millions of animals have been killed. Mutations create concerns that they will render a vaccine ineffective. The virologist Christian Drosten, however, sees the killing as a political precaution.

more on the subject

Mutations of the SARS-CoV-2 virus are probably not a threat to humans

Corona infection - after the tiger, the domestic cat