• Dogs' remarkable sense of smell allows them to sniff out drugs and possibly cancer and abnormal blood sugar levels.
  • All dogs have the capacity to separate smells and identify unique odors, but breed and personality play a role in choosing the best dog for spotting health problems.
  • In clinical studies, dogs have been able to sniff out stage 1 ovarian cancer, which is notoriously difficult to detect.
  • Scientists are hoping that dogs can detect an odor that occurs early enough in the coronavirus infection to identify people with asymptomatic COVID-19.

Video Transcript


JOHN WHYTE: You're watching Coronavirus in Context. I'm Dr. John Whyte, Chief Medical Officer at WebMD. Today we're talking about dogs, and I'm joined by Dr. Cynthia Otto. She is Professor of Sports Medicine at the University of Pennsylvania School of Veterinary Medicine. Dr. Otto, thanks for joining me.

CYNTHIA OTTO: Oh, it's my pleasure to be here.

JOHN WHYTE: Now, dogs have this remarkable sense of smell. We know it from their ability to sniff out drugs. Uh, there's some data in terms of being able to detect cancer, abnormal blood sugar, and now we're thinking about coronavirus. And you've been quoted as saying, dogs sniff in color. Wh-- what does that mean?

CYNTHIA OTTO: That's one of my favorite ways to try and equate how dogs perceive the world. So we are very visual as humans. And so we can look around a room and we can see all of the different colors and the shapes and the textures, and we can pick out a very individual item. Say, like, Where's Waldo.

And so people are visual. Dogs do that same sort of thing with odor. So they can sniff and they-- they-- they take inventory of a room in the odors that it brings, and they can identify unique odors. They can-- they can identify what combinations of odors mean, and they're really good at picking up, you know, an individual and very-- potentially subtle odor.

JOHN WHYTE: Now, are particular breeds better than others? I always see Labradors when I see-- or retrievers. Maybe that's because I had a Labrador retriever. But are there particular breeds? Can a poodle do just as well?

CYNTHIA OTTO: So I think that pretty much all dogs have an incredible capacity to use their noses, because they really-- that's been how they navigated their world. If there's a breed that's not quite as good, I would say it's the sighthounds. Um, and having owned a greyhound, I would-- I would think that that's probably true.

But for the rest of our-- our dogs, I think that we really are looking more at the nuances. So everybody's at this basic level of competency, and then we have our superstars. Um, and so some of our superstars will be the Labradors. Because for generations, they've been selected for hunting. And so they have to use their noses.

But when we're talking about this kind of work, it's more than the breed. It's the personality. So what we found with our work is it's the dogs that are very focused and-- and very intense and really like that detail, sort of separating out the, you know, this belongs and this doesn't.

JOHN WHYTE: Now tell us about this study that you're working on. It's fascinating as we think about the role of dogs in the detection of coronavirus.

CYNTHIA OTTO: Well, what we're doing is building on 6 and 1/2 years of medical detection research. We started with ovarian cancer. We've-- we've actually done some studies with biofilm infections a-- associated with implants like hip replacements. And we were moving to a prion disease in deer as part of our program when suddenly we were facing COVID.

JOHN WHYTE: Tell folks what a prion disease is.

CYNTHIA OTTO: So, um, a-- a prion disease is this really strange-- it's-- it's an infectious disease, but it's not our classic infectious agent. It's like mad cow disease. So it-- it is a protein that-- that causes this disease, but it's transmissible.

JOHN WHYTE: Now, one of the big issues in coronavirus and transmissibility is that people are asymptomatic. They're infectious, yet they don't have symptoms. Do you think this could be an area where detection by smell could play a pivotal role?

CYNTHIA OTTO: We're excited that it might be. And-- and the reason that we can even have that hope is that we know in our ovarian cancer detection, the dogs were actually able to pick up patients that were at stage 1, which is really hard to detect otherwise.

And our colleagues in the UK that have done the work with malaria have been able to identify patients that are asymptomatic. So we're hoping that we'll be able to identify an odor that occurs early enough in the infection that we can actually pick up these asymptomatic individuals.

JOHN WHYTE: Now, when do you think this study might be done or will have good data to see if this is really practical and feasible?

CYNTHIA OTTO: OK, so those are three different questions. So,

JOHN WHYTE: Getting them all in. Getting them all in.

CYNTHIA OTTO: When the study will be done depends on which question we feel like we've answered. And so I think we've got a number of stages and a number of questions that we're looking to answer. Our first question is proof of concept. Is there a unique odor that the dogs can discriminate in samples from patients that are COVID positive versus COVID negative.

JOHN WHYTE: So we're still at that stage? OK.

CYNTHIA OTTO: Absolutely. We're-- our dogs are-- are pretrained, they're ready to go, and all we're doing is we're waiting for our receipt of our samples. So we have all of our regulatory, um, regulations have been approved.

When we're waiting for our colleagues at the-- the hospital at the University of Pennsylvania Children's Hospital to be able to hand off those samples to us so that we can, um, take them to the lab, inactivate the virus so that we're not dealing with an infectious or dangerous hazard, and then take those to the dogs and really work on having the dogs answer that question.

JOHN WHYTE: And viewers should know that these are dogs that are highly trained, correct? It's not-- it might not be our typical pet that, you know, we're playing with that's, you know, several years old. Is-- is that right?

CYNTHIA OTTO: These are very, very specifically trained dogs and they've been selected for the work that they can do. Um, and they've been in the pretraining phase to make sure that they're able to do this very intense, very focused, and precise work and have fun doing it. That's the other thing is that they-- we want dogs that are motivated and enjoy doing this kind of work.

JOHN WHYTE: And you are The Working Dog Center, and we-- we can see that sign in background. I have to be fair to my cat loving friends, so other than the dogs, is there a role for cats at all in-- in the coronavirus detection?

CYNTHIA OTTO: So the-- the absolute answer is no. And I love cats and I've actually trained some cats to do wonderful things, and cats have a great sense of smell. But we've got-- we've got two strikes against them. One is that they might actually be more susceptible to coronavirus, so we wouldn't want to put them in that-- that situation. The other is, they would have to agree to do this.

JOHN WHYTE: Oh, that's a good point. Yes. And finally, since you brought up about cats and coronavirus, what's the latest data? We've had conflicting information over time, or maybe I should say evolving information over time, about whether dogs can catch coronavirus and whether they can transmit coronavirus to humans.

CYNTHIA OTTO: Right. And so I think that it is a-- you know, we are still learning. There have been, I believe, four cases worldwide of dogs that have been confirmed with coronavirus. And there have not been any cases of confirmed transmission from dog to human.

So we believe that this is a pretty low risk. The dogs that have been confirmed, um, were in environments that were very heavily populated with people with coronavirus. And I've only really looked at-- at some of the dogs, the information about the dogs, but they did tend to be older and they may have had other complicating factors that actually put them at higher risk. That said, we're taking this very seriously and we will be monitoring our dogs and we'll be really trying to do everything we can to minimize any risk of undue exposure for these dogs.

JOHN WHYTE: Well, Dr. Otto, I want to thank you for taking the time to share information about this exciting study and to tell us about, uh, you know, how many of us know how fascinating dogs can be.

CYNTHIA OTTO: Well, thank you so much for having me and-- and allowing us to share. I'm-- I'm just excited that we have a wonderful collaboration with the medical community and the research community and the scientific community. And I think that hopefully it will bring some hope and maybe make a difference, um, for people.

JOHN WHYTE: Well, thank you again, and-- and thank you for watching Coronavirus in Context. I'm Dr. John Whyte.