What the scientific community has reported so far regarding the Sars-Cov2 virus that causes covid-19 disease is preliminary and most of the data is relative to its behavior in humans. It is not yet known exactly how much risk this pathogen represents for domestic animals and wildlife, since in several parts of the world cases have been reported in pets such as cats and dogs after having contact with infected people, as well as animals in captivity.
The Centers for Disease Control and Prevention in the United States (CDC, for its acronym in English), indicates of several lions, tigers, cougars and gorillas infected in zoos in New York, Texas, Tennessee and California, as well as leopards of the snows in Kentucky. The most obvious sign is coughing and they subsequently recovered.
According to the organization Wildlife Conservation Society (WCS), which is based at the Bronx Zoo, New York, in the case of felines, the virus was detected through tests carried out on fecal samples. It involves a Malayan tiger, three other natives and three African lions, all infected by asymptomatic workers.
The WCS ensures that there is still no certain evidence that animals play a role in transmission despite the fact that there is a theory that is not definitively confirmed by the World Health Organization (WHO). In fact, Peter Ben Embarek, head of a delegation from the agency that visited the city of Wuhan, China in February, said that they did not find conclusive evidence about the origin of the virus, without being able to determine which animal could transmit it to humans, but which yes it is a zoonotic virus.
The zoonotic source derives from zoonosis, that is, it is passed from an animal to a human through direct or indirect contact by touching the species, touching a fluid such as urine, saliva and through insects, among others.
Embarek added that a transmission of the coronavirus from one animal to another and then to humans is the hypothesis with the highest “probability”. However, they have not identified such species. In the Chinese city of Wuhan, Hubei province, it was the place where the first two infections of the current pandemic were detected in December 2019. Much was said about its origin and one of the most mediated theses is the consumption of bats in the gastronomic field.
The World Organization for Animal Health (OIE) has a record on its web portal of some 27 countries in which infections have been reported in pets, zoo and wild animals. Regarding the latter, it is a wild mink in Utah, USA, which underwent a PCR and nasal swab test, and was named by the OIE as the first case of a wild in the wild that is a carrier of the virus.
The data collects cases of cats, dogs, minks, felines and ferrets in the Netherlands, France, Spain, Belgium, Germany and other European nations, as well as Russia, China and in Latin America: Chile, Argentina, Brazil and Mexico. Particularly in the US, specialists have observed respiratory infections and deaths of minks found in hatcheries.
Animals with high susceptibility to infection
According to the United Nations (UN), in addition to Denmark, the Netherlands, Spain, Sweden, Italy and the United States have reported the appearance of the virus in farm mink, and after several investigations by international laboratories it is known that cats, ferrets, fruit bats, and hamsters are the most likely to contract Covid-19. The first four can even be a transmission factor for others of the same species. Shrews can get it too, just like dogs, but to a lesser degree.
A very particular study is that of the monkeys or rhesus macaques, one of the primates that share physiological characteristics with humans and is used mostly to develop and test drugs, prior to clinical trials. In addition, crabby macaques, green gingerbreads and marmosets are all species that can acquire the infection inside and outside an experimental environment, according to the study, demonstrating how vulnerable people are to this virus.
Luis Serrano, professor at the Catalan Institution for Research and Advanced Studies (ICREA), explains that it is very important to know which animals have the greatest susceptibility in order to prevent the virus from staying and “can re-emerge over time ”, Especially in the case of mink and ferrets, which are species that tend to be in places close to humans.
But ultimately, the Center for Genomic Regulation of Catalonia, Spain, concludes that after humans, the species of ferrets, cats, civets and dogs, among 10 species analyzed, are the most susceptible to infection, while ducks , rats, mice, pigs and chickens are less sensitive to Covid-19.
The role of pets in the spread of the virus
Symptoms linked to the disease in pet cases confirmed to date are respiratory and digestive, but experts say that it is highly unlikely that a domestic animal can transmit the virus to people. The reported links do not show that infected pets infect their owners, on the contrary; dogs and cats have tested positive after contact with people.
It is possible that this occurs after the caretaker, who is infected, strokes or touches their fur, but it is a theory, says Rachael Tarlinton, professor of veterinary virology at the University of Nottingham in England, United Kingdom. Considering that specialists are still learning the dimensions of the virus and how it can affect animals; that the cases in these are minimal and that the symptoms they present are mild, in addition that animals killed by the infection are not registered, particularly domestic dogs and cats are not a threat.
This has been endorsed by the Center for Foot-and-Mouth Disease and Veterinary Public Health of the Pan American Health Organization (Panaftosa) and the organization World Animal Protection, in a statement. "To date, there is no scientific evidence that companion animals, dogs and cats, are a source of infection for humans."
“There is no evidence that dogs can get sick and the infection in cats is being investigated. The recommendations continue to be to wash your hands before and after interacting with them, as well as to practice distancing yourself if you are sick, ”the joint document specifies.
The text also points out that the misinformation and uncertainty that the covid represents affects the well-being of pets, since "many people associate that their pets could get sick and spread the virus" leading them to abandon and sacrifice them, leading to public health situations , they assure.
The mink as a reservoir for Covid-19
Regarding the mink, there have been very relevant events in Denmark, Spain, France and the Netherlands, whose authorities euthanized millions of specimens of this species after they detected a variant. In Denmark the massacre triggered a political crisis because it was authorized without a legal basis. Some 17 million farm minks were euthanized on the grounds that the mutation reduces the response to antibodies to the vaccines that are developed.
It was the Danish Prime Minister, Mette Frederiksen, who explained that the mink can become a reservoir of the virus with the mutation - of the many that are now known to have emerged - and be a factor of spread for people. Millions of minks in that country and others in the European Union (EU) are raised as raw material to make products for the textile industry.
In this regard, the OIE recognizes that there is concern about the circulation of new variants that may result in the improvement of transmissibility or virulence by the virus towards humans. However, "all the consequences are unknown and more research is needed to fully understand the impact of these mutations," which is why the impending slaughter of minks in Denmark was rejected by the WHO and other experts.
By the end of 2020, the UN agency specified that it was very premature to affirm that this mutation, called Cluster 5, has changed the contagion capacity and severity of the virus towards humans, nor that it has consequences on the efficacy of a vaccine.
“You have to understand that this kind of thing happens. This is a pandemic and millions of people and animals have been exposed (…) We have seen several infected animals and there is always the possibility that the virus will return to humans, something that is worrying because minks are ideal hosts for it to mutate, especially when there are so many and they live crowded ”, emphasized the director of emergencies of the WHO, Michael Ryan.
The same multilateral organization details that this variant associated with minks has a "moderately reduced sensitivity" to neutralizing antibodies, but requires more scientific and laboratory studies to verify. Together with the Food and Agriculture Organization of the United Nations (FAO) and the OIE, they conclude that mink fur farms can have a significant impact on livelihoods, public health and wildlife.
A greater situation as a consequence of the pandemic in these places would be “a generalized socioeconomic alteration (…) and poses a risk of spreading to native wildlife that can affect the biodiversity of the species,” cites a risk assessment by the global tripartite.
OIE and WHO general considerations
- The WHO highlights that most viruses have animal origin, but that in the case of SARS-CoV-2 this has not yet been confirmed.
- The available data refer that the genetic sequence is the one that circulates in horseshoe bats. However, there is not enough evidence of the origin.
- What is a fact is that several species of animals have demonstrated susceptibility to the virus in experimental inductions and when they have contact with carriers.
- Some infected animals can transmit the virus to others of their species such as minks, which are highly susceptible, and from minks to cats.
- Not all species appear to be susceptible, as experimental infection studies in poultry and cattle demonstrate this.
- Infection of animals with SARS-CoV-2 has implications for human and animal health, wildlife, and biomedical research.
- There is concern regarding reservoirs in animals that may pose a public health risk and lead to future events.
- The virus in populations of endangered animals could undermine conservation efforts and cause the loss of their biodiversity.
- More research is required to fully understand these risks.
- The first reported cases of transmission from an animal to humans are those related to mink.
- Follow up on OIE updates.
- To protect your pet from the virus, do not let him interact with people or animals outside your home.
- Avoid taking your pets to parks or places where there are large numbers of people and animals; keep it at a distance.
- If you are a carrier of the virus, have another trusted family member or friend take care of your pet.
- Avoid stroking, kissing, licking, or sleeping in bed with your pet.
- Wear the mask, wash your hands before and after handling food, waste and touching the animal; constantly clean your home.