In the past three years, people’s lives have been inconvenient due to masks. Since the outbreak, more than 70,000 people have been diagnosed with the disease in our country. Recently, outbreaks have also occurred in many other countries. It can be s...
In the past three years, people’s lives have been inconvenient due to masks. Since the outbreak, more than 70,000 people have been diagnosed with the disease in our country. Recently, outbreaks have also occurred in many other countries. It can be seen that this virus is extremely transmissible among humans.
As the epidemic spreads, rumors are flying everywhere. The so-called "pets can also be infected with the new coronavirus" has caused some pet owners to panic about whether their pets are infected and spread the virus, leading to abandoned pets and even cruelty and killing of pets. But it was ultimately confirmed that no infection cases were found in a large number of pets that have close contact with humans, such as cats and dogs. The new coronavirus is so powerful, why are cats and dogs, both mammals, immune to infection? The new crown virus belongs to the Coronaviridae family in classification, including four genera, including α, β, γ and δ, and can infect a variety of animals, including humans. Among them, alphacoronavirus mainly infects humans and pigs, dogs, cats, bats, etc.; betacoronavirus mainly infects humans and mammals such as cattle, horses, pigs, mice, etc.; gammacoronavirus mainly infects chickens, turkeys, ducks, geese and other poultry, and deltacoronavirus mainly infects wild birds and pigs. Canine respiratory coronavirus was isolated from dogs with respiratory disease symptoms in 2003. It mainly causes respiratory diseases. The symptoms of infected dogs usually are not obvious or mild. Feline coronavirus often causes intestinal infections in cats. Most infected cats have transient upper respiratory tract or diarrhea symptoms, and the infection usually resolves within a few weeks. Occasionally infected cats develop highly lethal immune-related vasculitis with high mortality. In general, the coronavirus that infects dogs and cats is mainly of the alphacoronavirus genus, while the one causing the new coronavirus pneumonia epidemic belongs to the betacoronavirus genus. Coronaviruses are widespread in nature and have strong variability. The genes of coronaviruses in humans, dogs, and cats are very different. The canine coronaviruses and feline coronaviruses currently detected and isolated are different from the coronaviruses detected in infected people during the new coronavirus epidemic. Although they are both called coronaviruses, they have low nucleotide homology and are not the same type. Since the outbreak of the new coronavirus, scientists have found a therapeutic target in a short period of time: angiotensin-converting enzyme 2 (ACE2). The SARS virus and MERS virus that have caused huge losses to humans in the past have an S protein that can bind to the ACE2 protein.
For example, the three coronaviruses that once seriously threatened human health were able to easily invade our cells because they had the "key" of S protein, which happened to match the "door lock" of ACE2.
However, cats and dogs lack ACE2 receptors, so they cannot bind to the S protein of the new coronavirus, and they cannot infect cats and dogs. Cats and dogs will not become virus carriers of the new coronavirus. A recent study conducted throat swabs on 20 pet cats and 4 pet dogs with diarrhea and respiratory symptoms (especially fever and severe cough) in Beijing, and samples were taken for nucleic acid testing. The results showed that no pet dogs or cats were positive for SARS-CoV-2 nucleic acid, and the disease was caused by infections such as herpes virus and mycoplasma. Although the number of samples in this study is small and not representative enough, judging from the current situation, cats and dogs who are in close contact with infected people do not show signs of a large number of illnesses, and the infection rate of healthy people who are in close contact with cats and dogs in epidemic areas has not increased significantly. This shows that the new coronavirus is mainly transmitted from person to person, and there is no need to be taboo about continuing to have close contact with our pets.
