Can dogs sense when you’re sick? Surprising Answer

History of Dogs Sensing People are Sick

A dogs sense of smell has always been a powerful and amazing trait, even when dogs were undomesticated and wild. Dogs rely on their sense of smell for many different things, from hunting for food to sniffing out their favorite stuffed animal toy! Dogs sense illness through the chemical changes in our bodies, so it is likely dogs were able to detect illness in their humans for thousands of years.

Dogs are also able to detect sickness in fellow dog companions, as well. If you have ever seen a dog intently licking a spot on another dog and then find there is a sore or scrape there, this is because the dog can sense it and they are trying to help the affected dog.

However, it was not until relatively recently that science has been able to confirm how dogs are able to sense illness and that they can indeed sense illness in humans and other animals. Dogs are now specifically trained to detect illnesses in humans. Some dogs are trained to actually detect the early stages of cancer in humans and not just minor illnesses like a cold or the flu.

Although I’m of the firm belief that my dog is a unique and special angel, it’s easy to find tales of other pets comforting or guarding their people during times of illness or injury. I was sick last week, and as Midge was glued to my side, friends told me about their own pets attending to them around the clock after everything from surgery to stomach troubles. (For the record, Midge didn’t care when I sliced my hand open while washing dishes last month.)

I will do anything I can to avoid admitting I’m sick. I take a double dose of my usual allergy medication when my nose gets stuffy. I blame my building’s dry heating system for my scratchy throat. I chalk up my lethargy and malaise to the fact that I spend roughly 14 hours a day on the internet.

Midge, my 12-pound rescue pup, isn’t the world’s most affectionate dog. We get along great, but she has her own hobbies: horrifically dismembering her cute little plush toys, chewing through her chew-proof bed. But as soon as even a mild head cold starts to take hold of me, my dog is transformed. She’s no longer her usual self, jabbing a dagger paw into my ribs to prod me into throwing her ball. Instead, she’s Doctor Midge, Medicine Chihuahua, ready to nurse me back to health by cuddling up against me (or on top of me) at all times.

According to researchers who study canine cognition, it’s usually not just pet owners’ imagination. Pups really do know when their humans are having a rough time, and they use a rich variety of signals to figure it out. Not only can your pet tell when you have the sniffles, but domestic dogs have shown an aptitude for detecting both much more minute mood fluctuations and far more serious physical conditions.

“Dogs are preternaturally sensitive to changes in their people,” says Alexandra Horowitz, the head of the Horowitz Dog Cognition Lab at Barnard College. “If a person is infected with a virus or bacteria, they will smell different.” Some illnesses change a person’s odor so profoundly that even other people can notice it, but dogs are able to smell changes in their people that would escape human senses, or that are so early on that the sick person barely feels any different. That’s because dogs have exponentially more powerful senses of smell than humans: They can have as many as 300 million olfactory receptors in their nose, as opposed to a paltry 6 million for the average person.

“Dogs have been shown to use their noses to reliably detect melanoma, but that doesn’t mean our canine friends are likely to be used in place of lab tests,” Golden says. Instead, researchers are working to better understand how a dog’s (or other mammal’s) nose can be so much more sensitive than current medical testing.”

“Since Hippocrates, it has long been speculated that diseases might be diagnosed based on odor,” says Dr. Golden. “Over the last decade, studies have shown that the volatile organic compounds (VOCs) found in urine, feces, breath, or other bodily emanations have been successfully used to detect disease or infection. This has led researchers to conclude that VOCs found in waste are a window into the body.”

This means dogs’ ability to detect illness goes beyond their sense of smell. Since the average dog hasn’t been trained to alert people to the presence of diseases, the reason your dog seems to know when you’re sick probably has little to do with odor — and a lot to do with their relationship to you.

Dogs can learn to detect various diseases, including diabetes and breast cancer, by sniffing urine, sweat, and breath. And some researchers are currently training dogs to detect COVID-19. In fact, a recent study found that trained dogs are better at detecting COVID than rapid antigen tests. A dog can be a reliable way to sniff out (literally) certain illnesses. But sometimes, dogs pick up on conditions or medical events for reasons that are less clear.”

If it ever seems that your dog has the uncanny ability to tell when you’re sick, it’s not all in your (stuffed-up) head. From reading body language to actually sniffing out disease, dogs have several ways they can pick up on illnesses. We did a little digging, including checking in with Dr. Glen Golden — a research scientist at Colorado State University’s Department of Biomedical Science — to find out just how far a dog’s detection skills go.

Scientists Confirm Dogs Can Detect 8 Diseases

Despite groundbreaking technology and new breakthroughs in medicine, for some patients, the best remedy is a four-legged companion. Over the past 30 years, the rise of therapy dogs has proven that dogs have tremendous healing power, from decreasing stress to even detecting imminent diseases.

It might sound too amazing to believe, but studies have proven that dogs are the next best thing to having a 24/7 doctor. And even better? They are excellent at providing support when we need them the most.

It’s no surprise dogs have mastered body language. After all, they have to survive in a world full of people who don’t speak in barks. Dogs’ sense at noticing subtle shifts in behavior comes in handy when our emotions take a nose dive. The people around us might not notice when we’re feeling sad or sick, but dogs do. Slumped shoulders, fragile movements, and immobility are all things your dog notices, and once they do, they come to provide comfort.

“Dogs know [when] something is different, whether the smell changes or they are moving less,” Dr. Bonnie Beaver, professor at Texas A&M University’s College of Veterinary Medicine, told the Associated Press. “That’s how they read each other. They are great at it, and we are not.”

And we’re not talking about the “warm fuzzies” either. Scientifically, dogs make us happier through mere touch alone. According to a study conducted at The University of Missouri Health, petting a dog releases all kinds of beneficial hormones, like endorphin, prolactin, dopamine, oxytocin, and beta phenylethylamine. These hormones make us happier and open a path to healing, which can mean the world to a person suffering from anxiety or mild depression.

You would think dogs being unable to talk would be a hinderance, but it’s actually the opposite. Because dogs don’t speak our language, they’re non-judgmental and accept us as we are, according to Creature Comfort: Animals That Heal by Bernie Graham. They also provide a needed break from human interaction when we’re not feeling emotionally able to handle it. Whatever social barriers that make communicating with human caretakers difficult aren’t a problem with a dog.

When dogs comfort us, a domino effect happens. First, they make us happy and less stressed, according to WebMD. This increase in happiness then makes us more active, which in return improves overall health. For years, doctors have cited happiness as the key to being healthy. When dogs comfort us, they boost our entire well-being.

In 2006, a medical study reported how ordinary non-trained dogs could identify breast and lung cancer patients by smelling their breath. Although the theory of dogs being able to detect diseases is still a new one that’s being studied, dogs’ keen sense of smell means they can detect subtle shifts in our chemical balance that we don’t always notice ourselves. When dogs sense this, they know to come to our aid, providing the kind of healing companionship that only a pet can provide.