Talking Animals: How common is it for human diseases to be transmitted with pets?

While alarms to continue to sound over ever-rising cases of coronavirus, some pet owners have been left wondering what this all means for their health of their pets.

University of Windsor anthrozoology professor Beth Daly talks COVID-19 and our animal friends

Anthrozoology professor Beth Daly joined Tony Doucette in the studio to talk about COVID-19 and animal friends. (Tom Addison/CBC)

While alarms to continue to sound over ever-rising cases of coronavirus, some pet owners have been left wondering what this all means for their health of their pets.

In Hong Kong, a 17-year-old dog that had recently been cleared of the coronavirus after initial suspicions of infection were proven unfounded died two days after it was released from quarantine, officials said this week.

Anthrozoology professor Beth Daly joined Tony Doucette in the Windsor Morning studio to talk about how common it is for diseases to be transmitted from humans to animals — and vice versa.

How common it is for animals to catch a virus or an illness from a human?

This is something that people think about a lot because we're always hugging our animals and they're in bed with us. Just the other day on my Facebook page, several of my colleagues were commenting on a post that said, 'Do not worry. You cannot catch this from your dog.'

My understanding is it's not that common for our everyday diseases to go to animals. We call this by the way reverse zoonosis. A zoonotic disease is a disease that is passed between people and animals. So reverse zoonosis is something that an animal catches from us.

A dog wearing a mask is seen at a main shopping area, in downtown Shanghai, China, as the country is hit by an outbreak of a new coronavirus, February 16, 2020. (Aly Song/Reuters)

There have been these strange one-off cases that I've read about where, for instance, a Yorkie caught tuberculosis from a human years ago — it was a documented case. But these are these kinds of things were unusual.

One thing people need to be aware of is MRSA which is a staph bacteria, the superbug that we've often heard about. I used to take my dog to do volunteer work at the hospital and I would put socks on her because then she comes home and jumps on my bed. That is something that dogs can actually give to humans. MRSA is one of the big ones that we've often heard about.

We hear of diseases like bird flu and swine flu. Did they come from animals originally?

Indeed, yes they did. HIV, Ebola, flu and malaria — these all come from animals. Malaria comes from mosquitoes. This is exactly where they come from. Influenza is a zoonotic source.

We like to be affectionate with our pets. We even cuddle them — our dogs and cats in particular. Does that pose a health risk?

I don't want to be the bearer of bad news, but it could. The question is: where has your dog been? And where has your dog's mouth been? One thing about cats is that they can shed toxoplasmosis. For people who are immunosuppressed, that can be serious.

Somebody, for instance, who is going through chemotherapy, who is sick, even pregnant women are considered to be at risk for toxoplasmosis. So we probably should be very careful if you're around cats and you fall into one of these risk categories.

What about allowing your dog or your cat to lick you? Let's deal with cats first.

I have read that many people who are not animal lovers would probably be mortified. We can pick things up from our animals, depending on where their mouth has been. Some dogs have the absolutely disgusting habit of eating cat excrement So it is possible that a dog's mouth could be in contact with something like toxoplasmosis and we don't want that to spread.

What about the idea that a dog's mouth is the cleanest thing you could possibly imagine? Is there any truth to that?

I would really take a bottle of hand sanitizer over a dog's mouth. It depends where your dog's mouth has been. Let's be realistic. If your dog has has just eaten a can of tuna fish, I don't want her licking my face. So it depends where your dog's mouth has been. We have to consider that's probably more of a saying than an accuracy.

Dogs wearing masks are seen in a stroller in Shanghai on February 19, 2020. (Noel Celis/AFP/Getty Images)

We have a very strong immune system. I think if somebody were really concerned about their immune system, that might be something that we should avoid. But the reality is most of our big scary diseases have come from animals — not dogs, but certainly, monkeys and chimps have been responsible for some of these these big ones that are scary.

Do animals generally like being pet and hugged by humans, or is it something they just tolerate?

There's something called a consent test that is common for schools and educators now to teach children about dogs. Pet your dog, stop petting your dog and see what your dog does. Does your dog want to be pet? Many dogs will start pawing or leaning in because they want to be pet. This, by the way, is a way of teaching children there's times when you don't want to be touched and there's times that your dog doesn't want to be touched.

So a consent test is a way of asking your dog if they're in the mood to be pet right now. Many dogs are, and then they'll just sort of get up and walk away when they're done. So we can ask our pets if they're in the mood to be pet.

Would you say that pets are really beneficial in terms of mental health?

There has recently been some literature that is exploring this very question. One of the problems in anthrozoological literature is that we have not been diligent about doing scientific research, especially with the explosion of this research area. A lot of it is anecdotal which begs for further research.

A dog wearing face mask is seen on a street as the country is hit by an outbreak of the novel coronavirus, in Shanghai, China March 2, 2020. (Aly Song/Reuters)

I have a colleague who's actually been investigating whether or not pets improve people's depressive moods. While most people, anecdotally, say absolutely, the researchers is exploring this more and more and it's saying that it may not be that clear cut.

I think some of the contributing factors are a sense of worry or anxiety when we have an animal to take care of. That's currently under scientific investigation. Anecdotally, I would say that if you ask people, they would say absolutely. In my own experience, I have gotten through a lot of things because of my stormy cat when I was a child and my current dog. I think most people would say 'without a doubt' their pet brings them a lot of emotional satisfaction and greater mental health.

Answers have been edited for length and clarity. Listen to the full interview below:

With files from Reuters