Thehas moved at such a blistering pace that many fundamental questions about where the virus came from and how it spreads are still yet to be definitively answered. But thanks to a trove of research on previous coronavirus epidemics, scientists have shown this family of viruses can jump from bats into other species, like civet cats and camels.
The coronavirus, which causes COVID-19, is similar to previous coronaviruses in this way. It isn't particularly fussy when it comes to infecting mammals. The virus is able to hijack cells by interacting with a cell surface protein, known as ACE2, present in many animals, including cats and dogs. Because the virus has been shown to jump across species -- and thanks to some anecdotal reports about COVID-19 in pets -- owners are understandably worried about how COVID-19 could affect their companion animals..
Some media reports have shown the coronavirus can infect our companion animals. Two pet cats in New York state tested positive, marking the first US cases in companion animals, according to the Centers for Disease Control and Prevention, and have tested positive as well. But cases remain rare. It appears transmission of the disease from human to animal is low, with a tiny number of cases reported since the outbreak's early days. Importantly, there is still no evidence pets can transmit to their owners. The World Health Organization says there's "no evidence that a dog, cat or any pet can transmit COVID-19."
We've gathered everything you need to know about coronavirus and your pets here, along with emerging research in how animals may spread or be affected by the coronavirus. If you have additional questions, you can reach out via email or give me a nudge on Twitter.
- Where did the coronavirus come from?
- Can the coronavirus infect cats and dogs?
- Can other animals be infected?
- Can I get COVID-19 from my pet?
- How can I protect my pets?
- Is there a vaccine for COVID-19 in dogs and cats?
Where did the coronavirus come from?
This coronavirus, SARS-CoV-2, is what's known as a zoonotic disease: It jumped from an animal species into humans.
Studying the genetic makeup of the coronavirus and comparing it to a library of previously known coronaviruses, experts suggest the virus likely arose in Chinese horseshoe bats, before jumping to an intermediary species in close contact with humans. Some scientists believe the intermediary could be the pangolin, a scaly, ant-eating mammal that has been shown to harbor coronaviruses in the past and is one of the most illegally trafficked animals in the world.
Pangolins were sold at a Chinese live animal market often cited as the "epicenter" of the outbreak, but prestigious medical journal The Lancet published an extensive report on patients infected with the disease, noting that the very first patient identified had not been exposed to the animal market. The evidence that the pangolin was an intermediary remains scarce and some scientists believe the search should be widened.
Whatever the origin story of SARS-CoV-2, we know coronaviruses are able to establish residency in all manner of species -- whether they cause disease or not is a question that still requires an answer and it's an important one. Epidemiologists will want to know which species can harbor the virus so they can better understand where it may persist in the environment and how likely it is to jump back to humans in the future.
Can the coronavirus infect cats and dogs?
Coronaviruses are not particularly hard to please when it comes to potential hosts -- they've been detected in many mammal and bird species, including dogs and cats, as well as livestock like cows, chickens and pigs.
There have been several reports providing evidence of SARS-CoV-2 infection in household pets. A 17-year-old dog in Hong Kong repeatedly tested "weakly positive" for coronavirus in March and later died. A cat in Belgium tested positive for the disease on March 24. And two pet cats in New York tested positive in April, presumably after contracting the virus from people in their homes or neighborhood.
"These pets were living with infected human owners, and the timing of the positive result demonstrates human-to-animal transfer," said Jacqui Norris, a veterinary scientist at the University of Sydney in Australia. "Virus culture on these pets was negative, meaning that an active virus was not present."
A study, published in the journal Nature on May 14, looked at two instances of COVID-19 in dogs in Hong Kong -- the previously mentioned 17-year-old dog, a Pomeranian, and a 2.5-year-old German Shepherd. The study showed virus was in samples taken from the two animals but importantly there were no signs of illness. A second dog, a cross breed, was housed with the German Shepherd, but samples taken from the animal didn't detect any sign of the virus.
The authors conclude that human-to-animal transmission can occur but canine-to-canine appears unlikely.
Further evidence for how pets might contract COVID-19 comes from a study by researchers at the Harbin Veterinary Research Institute in China, published in the journal Science on April 8. It examined the susceptibility of a number of species to COVID-19, including cats and dogs, using a small number of animals.
The results demonstrated cats can be infected with the coronavirus and may be able to spread it to other cats via respiratory droplets. The team placed infected animals in cages next to three animals without the disease and found, in one case, the virus had spread from cat to cat. The felines didn't show any outward signs of illness, however.
Dogs appear to be more resistant. Five 3-month-old beagles were inoculated with SARS-CoV-2 via the nasal passage and housed with two dogs not given the virus. After a week, the virus was not detected in any dogs, but two had generated an immune response. The two dogs that didn't receive the virus didn't acquire it from their kennel mates.
One of the key takeaways is that these experiments were performed in a laboratory setting and high doses of the coronavirus were used to infect the animals, which likely doesn't reflect how the virus would spread in real life. Nevertheless, cats do appear prone to infection, and the authors note further monitoring should be considered.
IDEXX Reference Laboratories, a consortium of testing labs across the globe, announced in March that it had created a testing kit for felines and canines. After running tests on over 4,000 specimens from the US and South Korea, it found no positives. The US Department of Agriculture has stated it won't test companion animals unless testing is agreed upon by animal and public health officials due to "a link to a known human case of COVID-19."
Can other animals be infected by SARS-CoV-2?
Many species are susceptible to infection because they contain a protein known as angiotensin-converting enzyme 2, or ACE2.
That's because the virus itself is covered in spiky projections that can latch onto ACE2 proteins on the surface of animal cells. The coronavirus "spikes" then lock into place and hijack the cell to replicate.
Using computer databases and modeling, researchers have examined the genes of species to find out if the ACE2 protein in their cells can be used by SARS-CoV-2. A recent study, published in the journal Microbes and Infection on March 19, showed SARS-CoV-2 could grab onto the ACE2 receptor of many different species -- including bats, civet cats and pigs -- and predicted it may also be able to do so in goats, sheep, horse, pangolins, lynx and pigeons.
The research undertaken by the Harbin Veterinary Research Institute in China suggests that the virus replicates poorly in chickens, ducks and pigs.
The first confirmed case of coronavirus in an animal in the US was documented on April 5, when 4-year-old Nadia,, was found to have contracted the virus, likely from an infected but asymptomatic zookeeper. -- but most showed mild symptoms and were expected to recover.
Can I get COVID-19 from my pet?
There's still a lot we don't know about transmission of SARS-CoV-2, but the most important point to reiterate: There is a lack of evidence the coronavirus is spread by pets and companion animals to humans.
"There is absolutely no evidence whatsoever that companion animals play any role in the epidemiology of this disease," said Trevor Drew, director of the Australian Animal Health Laboratory. Drew and his colleagues at the AAHL arein pre-clinical trials to assess safety and efficacy of new treatments. Ferrets are used in the trial because they are particularly susceptible to infection by the coronavirus. However, even ferret owners are unlikely to get the disease from their furry friends according to Drew.
He notes that the researchers at the AAHL are not seeing "overt clinical disease" in their ferrets, but "they do seem to have a slight temperature and they do replicate the virus." It may be that SARS-CoV-2 can infect these animals, but cannot replicate enough to cause the set of symptoms which define human COVID-19.
You may also be wondering if you can pick it up from your pet's fur? The risk is low -- but not zero -- becauseand is able to be transmitted via droplets. Theoretically, it might persist on fur, so you should always wash your hands before and after you interact with your animals, especially if you're feeling unwell.
"People appear to pose more risk to their pets than they do to us," said Glenn Browning, a veterinary microbiologist at the University of Melbourne, Australia.
How can I protect my pets?
If you are feeling unwell and believe you may have contracted COVID-19, the first thing you should do is get tested. If you suspect you are unwell, the recommendation from the US Centers for Disease Control and Prevention is to "restrict contact with pets and other animals, just like you would around other people."
The best method of protection remains prevention. There are a huge number of resources available from the WHO on reducing your risk of infection, and the key measures are outlined below:
- Wash your hands: For 20 seconds and no less! You can get some .
- Maintain social distancing: Try to keep at least 3 feet (1 meter) away from anyone coughing or sneezing.
- Avoid touching your face, eyes or mouth: A difficult task, but this is how the virus initially gets into the body.
- Respiratory hygiene measures: Cough and sneeze into your elbow!
If you are sick, you may consider quarantining your pets at home and limiting your contact with them as much as possible. You don't have to isolate them, but try to limit them to one or two rooms in the home, wear a mask when around them and -- yes, we're saying it again -- wash your hands.
Is there a vaccine for COVID-19 in dogs and cats?
As with humans, there is no vaccine available against COVID-19 at this time. There is a canine coronavirus vaccine, but it is directed against another member of the coronavirus family and does not provide protection against COVID-19 (Note: The Australian Veterinary Association does not recommend it even for that virus).
There are. While some could theoretically be tweaked for different species (and some will even be tested in them), the most promising vaccines in development right now are being designed solely for use in humans.
Originally published in April and updated with new information regularly.