4 min read


Can a Dog Tell if You are Sick?



4 min read


Can a Dog Tell if You are Sick?


Dogs are amazing! With their finely tuned sensory organs, they can detect signs of illness. Their acute sense of smell is so strong they can detect changes in the chemicals in your body and sense your mood or a difference in your metabolism. 

Dogs are sensitive to body language and temperature. They can detect hormonal changes and even sense if you are pregnant. Dogs can smell different chemicals released by the body and this enables them to be aware of disease and ill health. Your dog knows you inside and out. They are your devoted companion in sickness and good health. 


Signs Your Dog is Sensing You are Sick

Your dog will always greet you with a good sniff, sensing the overall scent of you and where you have been. They will want to tune in to your well-being. Sometimes, dogs will try to smell embarrassing areas of your body, but this is all part of checking how you are and welcoming you home. 

A dog’s incredible sense of smell is known to be able to detect cancer cells and melanoma. Their abilities to sense changes in the chemicals in our bodies enables them to warn epileptics when a seizure may be about to happen. Dogs can smell lung cancer on a patient’s breath and even pinpoint the location of a mammary tumor. 

There are cases of dogs detecting bladder cancer and prostate cancer by the different smells of urine. A dog’s sensitive nose can detect blood sugar changes and the presence of ketones in diabetic patients. People suffering from epilepsy have the help of trained therapy dogs to alert them to the onset of a seizure. 

Dogs are super sensitive to changes in their owner’s moods and body language. Your dog will want to sit close to you and try to comfort you with their presence. They will know when you are not feeling well and can sense if you have a temperature. 

Dogs can understand your body language. Slumped shoulders and tired eyes just show you are not feeling yourself. Dogs are great comforters as they will just be there for you - nonjudgmental and supportive. Dogs have a calming effect and help patients with post traumatic stress and shock, as well as anxiety disorders. There is nothing quite as encouraging and reassuring as the love of a dog close by when you are not feeling well.  

Body Language

Some signs that your dog may give you if they sense you are sick include:

  • Head Tilting
  • Sniffing
  • Licking

Other Signs

More signs to look out for include:<br/>

  • Lying Close
  • Nuzzling
  • Watching You Closely

The History of Dogs Sensing Sickness in Humans


When we brought dogs into our family lives for companionship, we had no idea of the amazing effect they would have on everyone. Young and old, and those suffering from an illness, have all been touched by the support and love of an animal, especially from a dog. 

The first recorded therapy dog was a little Yorkshire Terrier called Smoky. His owner, Corporal William Wynne, was wounded and recovering from the war in the 1940’s. The corporal was being treated by Dr. Charles Mayo, founder of the Mayo Clinic. 

When Dr. Charles visited his patient, he saw what an amazing difference the 'Yorkie' had made to the corporal’s recovery. Not only was the corporal doing a lot better, but the other patients seemed to lighten up when the dog was around. Smoky became known affectionately as Yorkie Doodle Dandy. It was clear that this little dog had paved the way for other therapy dogs to be part of helping wounded soldiers and other patients with their recovery. 

This story does not end here, as Purina and the Mayo Clinic Foundation have decided to team up and study the benefits of animal assisted therapy. 

The Science of Dogs Sensing When We are Sick


There is definite scientific evidence of dogs being able to detect illness. Sometimes the illness can be life-threatening, and dogs have used their sense of smell to show doctors and specialists there are cancer cells, tumors and other changes in a patient’s body chemistry. 

Dogs can sense VOCs (Volatile Organic Compounds) that give specific odors - detectable by the canine's strong sense of smell. Dogs are being trained in this area to pinpoint tumors and their accuracy is remarkable.

Experiments also show that dogs have special healing qualities as they make patients happier by being able to pet an animal. The dogs help these patients to release beneficial hormones like endorphins and dopamine. These are hormones that make people happier and able to heal quicker.

Training Dogs to Sense When You are Sick


The training of service dogs and therapy dogs is specialized and extensive, but worth the time and effort, because of the benefits to people who need these wonderful dogs. Service dogs are trained to perform specific tasks and help people who are disabled. 

Therapy dogs have a broader role to play in helping the sick and emotionally needy people. If you feel your dog has the right temperament and could become a therapy dog there are certain behavioral requirements you need to have assessed before you can begin training your dog. 

An animal behaviorist or assessor can observe your dog and tell you if you can go forward with therapy training. Your dog needs to be caring and affectionate with a calm disposition. In addition, your dog needs to respond to certain basic obedience commands and you need to have control over your dog. Good therapy dogs know the following commands, sit, down, stay, come and leave. 

Most importantly, a therapy dog needs to be comfortable being touched, patted, and even hugged! Your potential therapy dog will be trained to keep calm in different circumstances. They will need to feel comfortable in crowded situations with strangers. The training will include exposure to wheelchairs, strange noises, and smells. Therapy dogs cannot be shy or over-exuberant. They must be in good health and not exhibit any negative behavior like growling while they are being handled. 

You, the handler will need training too, so you can be in control of your therapy dog as the two of you go out to visit patients in hospitals and old age homes.  It is a truly rewarding experience for you and your dog to take on therapy work.

Have questions or concerns about your pet?

Chat with a veterinary professional in the Wag! app 24/7.

Get Vet Chat

By a Rhodesian Ridgeback lover Christina Wither

Published: 06/18/2018, edited: 04/06/2020

Wag! Specialist
Does your pet have a supplement plan?

Learn more in the Wag! app

Five starsFive starsFive starsFive starsFive stars

43k+ reviews


© 2023 Wag Labs, Inc. All rights reserved.