WHO Let the Dogs Out?!

Note to the reader: Do not abandon your pets out of fear of the unknown.

Who (oh, WHO) is propagating the myth?

On March 11, 2020, the World Health Organization (WHO) posted on their myth-buster page stating that dogs cannot catch the coronavirus. The next day, the post was gone. Nevertheless, many people jumped on the opportunity to have a laugh at the obvious joke – that the WHO let the dogs out. The meme and joke perpetuated through social media, and many people assumed that dogs cannot get coronavirus – but where is the evidence?

Where did it come from?

On April 3, 2020, a survey was conducted of all literature published on the WHO website pertaining to the coronavirus and containing the words: dog, canine, pet, and animal.

Background: Didn’t the virus start in animals? Yes, potentially a bat! But before you jump to conclusions, let’s take a step back.

Coronaviruses are actually a family of viruses that are quite common. Most don’t affect humans, and there are a number of coronavirus strains that are quite common in dogs.2,3 Surprise outliers in this family included SARS-CoV in 2002, MERS-CoV in 2012, and SARS-CoV-2 (COVID-19) in 2019. Each of these three originated in bats. COVID-19 intermediate host animals (animals that could have gotten it from a bat, or given it to a human) likely include the pangolin, and have been hypothesized to maybe include snakes or minks.7 

Our Question: Can dogs, or other household animals, get sick and give it to humans?

Dogs, probably not. Cats, maybe.

The story started with a Pomeranian living with a COVID-19 positive owner.4 The Pomeranian, which tested weakly positive to the virus, triggered Hong Kong to release a statement advising “that mammalian pet animals including dogs and cats from households with … infected persons should be put under quarantine … to safeguard public and animal health.”5 A veterinary microbiologist commented that there was still no evidence to support human-animal spread at this time.5 Furthermore, although the test was positive, scientists have since commented that the virus levels in this dog were so low that “the dog was never contagious to other pets or people.”1

This could explain why the WHO has seemed uncertain on this topic. At this time there is not nearly enough evidence to show what the role of a pet dog is in the transmission of COVID-19.

A study from Harbin Veterinary Research Institute is among many universities initiating COVID-19 animal research. They have released an early version of their research, not yet peer reviewed and officially released, detailing an experiment looking precisely at this question.6 They tested 7 dogs, beagles, and suggested that the dogs are unlikely to be carriers for COVID-19. They tested pigs, chickens, and ducks which all were similarly not susceptible to the virus. They included 6 cats in the study and showed that cats can become infected and transmit the virus between cats. There is no evidence for cat-human transmission. Cat owners, please interpret this very limited data with caution. Continue to love your cat, perhaps don’t let it interact with cats owned by those you yourself are distancing from. 

Summary

There have been a few cases of dogs that have tested positive, but these have been weakly positive and are unlikely to have been able to transmit to humans. Experiments underway are building on the minimal data currently available. The data on pets is few and far between at this time. The public health focus should remain on preventing human-human transmission of COVID-19.

Practical Tips

The benefits of pet ownership for health and well-being are well-documented, reducing loneliness and anxiety, lending daily structure, and lifting mood.8 These benefits should not go ignored. If you are allowed by local authorities to leave your residence to walk your dog, be cautious if your dog interacts with other dogs – they will transmit like any other surface, of course, but they are unlikely to contract and grow the virus themselves and spread it to you. Continue basic hygienic practices such as washing your hands. Keep loving your pets.

BUST OR NO BUST:

Our myth: Dogs can’t get the coronavirus, WHO let the dogs out.
Result: No Bust. Myth-meter = 80/100 truthfulness.

Written by Jonah Latsky.

References

1. Almendros A. Can companion animals become infected with Covid-19?. Veterinary Record. 2020 Mar 28;186(12):388-9. http://dx.doi.org/10.1136/vr.m1194
2. Ng LFP, Hiscox JA. Coronaviruses in animals and humans. BMJ. 2020 Feb 19;m634. https://doi.org/10.1136/bmj.m634
3. More GD, Dunowska M, Acke E, Cave NJ. A serological survey of canine respiratory coronavirus in New Zealand. New Zealand Veterinary Journal. 2020 Jan 2;68(1):54-9. https://dx.doi.org/10.1080%2F00480169.2019.1667282
4. Pet dog confirmed to have coronavirus. Veterinary Record. 2020 Mar 7;186(9):265. http://dx.doi.org/10.1136/vr.m892
5. Grimm D. Quarantine the cat? Disinfect the dog? The latest advice about the coronavirus and your pets. Science. AAAS [Internet]. [cited 2020 Apr 5]. Available from: https://www.sciencemag.org/news/2020/03/quarantine-cat-disinfect-dog-latest-advice-about-coronavirus-and-your-pets
6. Shi J, Wen Z, Zhong G, Yang H, Wang C, Huang B, Liu R, He X, Shuai L, Sun Z, Zhao Y. Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARS–coronavirus 2. Science. 2020 Apr 8;eabb7015. DOI: 10.1126/science.abb7015
7. Xu J, Zhao S, Teng T, Abdalla AE, Zhu W, Xie L, Wang Y, Guo X. Systematic comparison of two animal-to-human transmitted human coronaviruses: SARS-CoV-2 and SARS-CoV. Viruses. 2020 Feb;12(2):244. https://doi.org/10.3390/v12020244
8. How pets are helping us through the coronavirus crisis. World news. The Guardian [Internet]. [cited 2020 Apr 5]. Available from: https://www.theguardian.com/world/2020/apr/03/pets-helping-coronavirus-crisis-animals