Veterinarian-written / veterinarian-approved articles for your dog.

Can Dogs Really Smell Cancer?

Can dogs really sniff out a person’s cancer?

Dogs definitely smell things differently and more intensely than humans do. That makes sense, since their ancestors needed to find food over great distances. They also use clues from pheromones to evaluate the health and emotional status of their pack-mates and to determine if there is a dangerous predator around. So it makes sense that, having been domesticated for thousands of years, dogs make use of their sense of smell to get along with humans, too.

Evidence That Dogs Can Smell Cancer

In a study done a few years ago, three German shepherds were trained to identify by smell specific compounds in the urine of men with prostate cancer. The dogs were then tested by being presented with urine samples from about 900 people, some of whom had prostate cancer and some of whom did not. The dogs all achieved extremely high rates of correctly identifying those with cancer, sometimes reaching 100%. They also had high rates of correctly identifying those without cancer, with rates reaching up to 98.7% (Gianluigi Taverna, 2015).

How Do Dogs Smell Cancer?

Cancerous cells produce different chemicals than normal ones, and dogs seem to be able to detect them. It's interesting to think about how much your dog might actually know about you but be unable to communicate.

The benefits of using dogs to help diagnose cancer could be tremendous. First, specific chemicals related to individual types of cancer would need to be identified, and dogs would need to be trained to separate that scent out from all others. Then, the dogs would be trained to indicate whether or not that scent was present in a sample. More research is necessary to determine how this could be clinically useful.

Dogs Help Humans Every Day

Whether they are sniffing out cancer, helping people with autism, serving as search and rescue dogs, helping people with physical disabilities maintain independence, helping people with PTSD cope with panic attacks, or just greeting us and making us smile after we've had a rough day, dogs can truly be humans' best friends.

Works Cited

  1. Gianluigi Taverna'Correspondence information about the author Gianluigi TavernaEmail the author Gianluigi Taverna, L. T. (2015, April). Olfactory System of Highly Trained Dogs Detects Prostate Cancer in Urine Samples. Retrieved from DOI: 10.1016/j.juro.2014.09.099.

You May Also Like These Articles:

8 Ways Dogs Can Help People with Health Conditions

Is It OK to Let Your Dog Lick Your Face?

Autism Service Dogs

Dogs Make the Best Matchmakers

Things We Do That Annoy Our Dogs - Slideshow

5 Dogs (or Dog Teams) Made Famous by History

Street Kiosks Care for the Planet and Stray Dogs in Istanbul: A VIDEO

Earth Day: Ways to Observe Earth Day with Your Dog

Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed veterinarian. If you require any veterinary related advice, contact your veterinarian promptly. Information at is exclusively of a general reference nature. Do not disregard veterinary advice or delay treatment as a result of accessing information at this site. Just Answer is an external service not affiliated with

Notice: Ask-a-Vet is an affiliated service for those who wish to speak with a veterinary professional about their pet's specific condition. Initially, a bot will ask questions to determine the general nature of your concern. Then, you will be transferred to a human. There is a charge for the service if you choose to connect to a veterinarian. Ask-a-Vet is not manned by the staff or owners of, and the advice given should not delay or replace a visit to your veterinarian.