Your Dog’s Amazing Sense of ‘Knowing’

Your dog has already parked himself in front of the door, waiting for a visitor who shows up moments later. How did he know?

Dogs have highly developed senses and instincts from their origins in the wild. They can see, hear and smell much wider ranges than humans. Their fur is like an antenna array, picking up all kinds of changes in the air.  Yet the most amazing attribute is their intelligence to put all this information together and act on it.

They can detect diseases and sense bad weather and natural disasters. And they understand you so precisely that they know when you need emotional support. Like many animals in the wild, dogs have internal clocks, and they are sticklers for routine. If you are off schedule, your dog will find out why.

Can a Dog Sense Bad Intent?
Is your dog greeting the stranger at your door with a wagging tail or a growl? First of all, your dog is looking at your facial expression and the way you move for clues. Are you eager, or hesitant? He is also watching the stranger for similar clues, and smelling them. You are the leader of your dog’s ‘pack’ and his primary job is to protect you. If your dog is upset, he’s trying to warn you that something is not quite right.

Distress, Depression and Fear
A study in 2018 found that when people cry, dogs will instinctively try to help. Those who could not push open a door to comfort their person felt helpless, becoming distressed themselves. Dogs also become distressed when they hear a baby cry. They are natural caretakers.

Dogs are attuned to people with precision. They are watching every movement, facial feature, action and tone of voice to sum up the situation and decide what they need to do about it. They may detect panic attacks coming before we know it ourselves.

A 2022 study revealed that when dogs were exposed to samples of sweat and breath taken from participants during stress-inducing experiences, even the worst dog in the group still identified the stress samples from the inert samples 90% of the time. The best dog was 96.88% correct. Your pet can even smell when you are having a bad day.

Storm and Earthquake Warnings
Canines have the ability to sense bad weather and seismic events. Studies show they can feel the drop in barometric pressure and possibly rising humidity levels and ionization in the air before a storm arrives.

One study of dogs with thunderstorm anxiety discovered that those who wore anti-static jackets did not panic or were less afraid, revealing that one of the ways dogs anticipate storms is by feeling electrostatic charges in their fur. (You can also help to reduce this anxiety-causing static with a damp towel or pet wipes.)

Also, because they can hear things very far away, and their sense of smell is about 100 times greater than ours, dogs may be able to sniff the ion changes or hear rain, or hear and feel rumbling coming in the case of an earthquake. If your dog is pacing nervously or whining, he senses something. If he goes to hide, something big could be coming. You might want to follow him.

Pregnancy and Labor Notice
Scientists are beginning to believe that dogs can detect hormone changes indicating when a woman is pregnant or about to give birth. It is unclear whether the dogs are detecting a change in hormones, or sensing something about the baby. More studies to come.

Diabetes and Seizure Alert
Dogs have shown amazing abilities to detect illnesses in people through certain ‘sick’ smells, sometimes called volatile organic compounds (VOCs) coming from breath and skin pores. Scientists have been trying to isolate the specific chemicals or proteins that attract the dog’s attention so they can devise a similar lab test.

Diabetic service dogs detect diabetes through a sugary scent in the urine or breath, or possibly through VOCs, and changes in a person’s activity. A service dog will bark or nudge the person to take action. They are trained to get the diabetes test kit or medications, open doors or drawers for the person, or go for help.

Seizure predicting dogs are trained to detect a certain scent that their person will release just before a seizure occurs. The dog will alert the person to lie down to minimize injuries, and bark to alert other family members, retrieve medications or press emergency buttons. Some dogs will instinctively get between their person and the floor to minimize a fall.

Even an average dog who detects illness will stay close by their person to watch over them.

Cancer Detection
Since the early 2000s multiple studies have been done to learn how dogs seem to know who has cancer. People with cancer emit very specific VOC ‘sick’ odors that most dogs and even some puppies will notice.

Studies show that dog diagnosis is 95% to 97% accurate , and they can often determine what kind of cancer it is, too. Even more astounding is how accurate they can be about the prognosis.

So there’s Buddy, sleeping peacefully in the corner. You had no idea he’s a doctor, a psychologist, a security system and a meteorologist. He sticks to you like a Secret Service agent, and he will do anything for you. All he wants in return is a hug and a nice meal. Good dog!


Heron's Crossing provides end-of-life care for pets in the Metro Atlanta area. In-home appointments with compassionate vets are available. If you'd prefer a home-like setting away from your home, our Decatur office is also available by appointment.