Science

Can pets get the vaccine? 5 Covid-19 questions answered by experts

Covid-19 can infect our furry friends — here's the 101 on Covid-19 and pets.

Illustration of dog and cat with face masks and Covid virus
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When the World Health Organization first declared Covid-19 a pandemic back in March 2020, it didn’t take long before humans began freaking out about their pets.

Scary reports began emerging, like the first dog who tested positive for Covid-19 dying — though it’s not clear whether Covid-19 was the cause of death — or reports of mass outbreaks on mink farms, leading many pet owners to wonder if their furry friends could get seriously infected from Covid-19.

But now that we’re more than a year into the Covid-19, how has our understanding of Covid-19 infection in pets changed?

For starters: we can now answer several questions about Covid-19 and pets, including:

  • Whether humans can infect animals (and vice versa)
  • Transmission between humans and animals
  • How pets get infected and whether they carry Covid-19 antibodies
  • Whether pets are likely to get seriously ill
  • Which animals are most susceptible to Covid-19
  • How to protect our furry friends from Covid-19

And a recent study published last month in the journal PLOS One may be able to shed even more light, revealing new information on Covid-19 infection in cats and dogs in Brazil.

Can pets get Covid-19?

A veterinary professional wears a protective face mask while petting a cat.

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The short answer: yes. We’ve known since the start of the pandemic that cats and dogs can become infected with SARS-Cov-2, the virus that causes Covid-19.

As time went on, research revealed that cats are fairly susceptible to SARS-Cov-2, though dogs appeared somewhat less vulnerable.

“Dogs can be infected with SARS-CoV-2, but studies undertaken under laboratory conditions have shown that dogs are less susceptible to infection than cats and fewer dogs than cats from Covid-19 households have tested positive for antibodies,” Margaret J. Hosie, a professor of comparative virology at the University of Glasgow who has conducted research on Covid-19 in pets, tells Inverse.

Dorothee Bienzle, a professor of veterinary pathology at the University of Guelph who has conducted research on Covid-19 infection in cats and dogs, agrees. Bienzle tells Inverse that “Mild illness appears to be more common in cats than dogs.” Her research found that some pets had Covid-like respiratory symptoms around the same time that their owners were infected.

Can pets give humans Covid-19?

A report also emerged in September 2020 that more cats had contracted Covid-19 in Wuhan — the world’s first major Covid-19 outbreak — than previously believed.

But Bienzle says there is “no evidence” that dogs or cats transmit the virus to humans or other pets. That fact has remained unchanged since the start of the pandemic.

But the opposite — transmission from humans to pets — does occur, and it may be occurring more frequently than previously thought.

According to the recent PLOS One study, which tested 39 pets for Covid-19, 28 percent of dogs and 40 percent of cats in the study also became infected with SARS-CoV-2 after their owners tested positive for the virus. The study authors write that “we have demonstrated that dogs and cats living in the same household as their owners with COVID-19 can be exposed and infected by SARS-CoV-2.”

However, Hosie isn’t as sure about the high rate of transmission, stating “Human-to-cat transmission appears to occur rarely,” which makes transmission to dogs even rarer. Her research only found one positive Covid-19 test out of a pool of 350 respiratory cat samples.

But as the evidence shows, transmission from humans to pets can and does occur, so pet owners should still be cautious.

“Nevertheless, people with COVID-19 should be aware that they can pass the virus on to their pets,” Hosie says.

Can pets recover from Covid-19?

Veterinarians treat a cat at the San Diego Humane Society in the early days of the pandemic.

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Overall, we still don’t know the exact rate of transmission between humans and pets, according to Bienzle.

“No clear answers in that regard, but this likely depends on how ill the humans are — how much virus they shed in their breath/cough/sneezes, and how much close time the pets and humans spend,” she says.

Yet, owners can breathe a little easier: there’s little evidence of cats or dogs becoming seriously sick.

“Severe illness is very uncommon in pets — much less common than in people,” Bienzle says.

Even when pets do get sick, they are likely to present as asymptomatic or show signs of mild illness — not severe Covid.

The study found:

  • only six out of the thirteen infected pets actually displayed mild symptoms
  • all symptoms appeared to be reversible — meaning pets were unlikely to experience long-term symptoms
  • all of the animals that tested positive had a “remarkable low viral load” according to the study, making even mild infection less likely

However, the study also notes that all of the pets were in fairly good health, which could be a limitation when applying its findings to older or weaker pets. Previous research suggests that older cats — much like humans — may be particularly at risk from Covid-19.

Furthermore, the study wasn’t able to paint a full picture on the length of Covid-19 infection in the pets sampled, stating “we could not determine the duration of viral elimination and antibody response in all animals with SARS-CoV-2 infection.”

However, according to Bienzle’s research, animals that get sick from SARS-CoV-2 develop antibodies, which could protect them against future disease. Roughly 60 percent of cats and 40 percent of dogs living with a person with Covid-19 developed antibodies, according to research Bienzle conducted in September 2020.

“We now have substantially more cases, but those numbers hold true,” Bienzle says.

Will pets ever get vaccinated for Covid-19?

A dog receives vaccine at drive-through clinic during the Covid-19 pandemic.

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Since many humans around the world are still struggling to get vaccinated, it’s hard to imagine pets being next in line.

“If the infection is controlled in people, it will also be controlled in animals. There is no evidence that pets have transmitted infection back to humans or to other pets,” Bienzle says.

Bienzle adds, “Therefore, our efforts should be placed at vaccinating all people.”

Even though pets aren’t yet eligible for the vaccine, some other higher-risk animals have already gotten the jab. Earlier in 2021, great apes at the San Diego received a trial Covid-19 vaccine.

“It is a possible consideration to vaccinate endangered animals in zoos that cannot be kept safe from infected people,” Bienzle says.

“Anyone with Covid-19 symptoms should avoid close contact with their pet, for example, they should avoid sleeping with their pet, kissing them, or preparing their food.”

The vaccine the great apes received was in the process of being developed for minks, which have suffered serious Covid-19 outbreaks on farms. Bienzle says that there is a legitimate concern about animals in crowded farm conditions, like minks, transmitting Covid-19 back to humans in a spillover event.

“We absolutely want to avoid that by management practices — vaccinate and test people [and] eliminate infection among mink through culling and/or depopulation,” Bienzle says.

Furthermore, the Russian government has just developed the first official vaccine for animals, creating 17,000 doses to be distributed across the country, though companies from other regions may seek to purchase vaccines from Russia.

Given these updates, Hosie believes that a pet vaccine might not entirely be out of the question in the near future, possibly reassuring worried pet owners. “It might be prudent to develop veterinary SARS-CoV-2 vaccines that would provide reassurance to pet owners that their pets will be protected from infection,” Hosie says.

Such vaccines would also remove the risk of pets transmitting Covid-19 to other animals or humans, according to Hosie. Bienzle stresses, though, that “vaccination is not 100% effective in people, and therefore also likely not 100% effective in animals.”

How can you protect your pet from Covid-19?

A dog, Ziggy, wears a face mask in Los Angeles.

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The main risk to your pet cat or dog is, well, you, unfortunately. The precautions you and other humans in your household take to keep yourself safe from Covid-19 will also reduce the risk of Covid-19 transmission to your pets.

“Given the value of the companionship provided by domestic animals such as cats, it is important to identify any risks associated with pet ownership, so that appropriate control measures can be taken to minimize transmission risk,” Hosie says.

The best thing you can do for your pet: get vaccinated. Bienzle says that vaccinated people have lower viral loads of SARS-Cov-2, reducing the likelihood that they will infect their pets.

Hosie agrees. “We have seen that if they become infected, vaccinated people are less likely to transmit the virus to other people, and so it is very likely that transmission to animals will be decreased too.”

The CDC recommends isolating cats and dogs from people not living in your household — though as vaccination rates increase, that advice may change. So, it’s best to keep your dog on a leash or keep cats indoors when possible.

If you do become sick with Covid-19, the best thing you can do is to social distance from your pet whenever possible. The authors of the PLOS One study write “that people diagnosed with Covid-19 should avoid direct contact with their pets for as long as they remain ill.”

Hosie agrees. “Anyone with Covid-19 symptoms should avoid close contact with their pet, for example, they should avoid sleeping with their pet, kissing them, or preparing their food.”

However, it may not always be possible to maintain distance from your pet. In those cases, follow the same protocol that would use when, say, going to the grocery store or shopping.

”Physical distancing plus mask is ideal. If physical distancing is not possible, wearing a good mask plus hand washing will reduce the likelihood of transmission,” Bienzle says.

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