Animals and Your Health: Dogs as Disease Detectors
En Español (Spanish Version)

There is no question that dogs can provide companionship, protection, and other services. But could there be another use for our canine friends? Some anecdotal evidence and a sprinkling of scientific studies suggest that dogs can detect seizures and cancers such as skin melanoma and prostate cancer.

Detecting Seizures
Though many anecdotal stories suggest dogs can alert their owners before a seizure, there has been little research on how dogs might detect seizures before they happen. Some theorize that the dog’s attachment to his owner helps in detecting subtle scent and behavioral changes. This has some researchers studying whether these skills could be taught.

Researchers in the United Kingdom found that the people using specially trained dogs actually reported fewer seizures. Though these results are promising, in most cases, it still seems that this skill is inherent in a dog’s personality, rather than something that can be taught. Future research may reveal what these dogs are detecting and how this information can be applied in the hospital setting.

There is no doubt that these dogs can alert help, help prevent injury, and watch over someone when they are having a seizure. However, the Epilepsy Foundation urges people to wait until research supports a specific training regimen for seizure predicting dogs.

Detecting Cancer
There has also been anecdotal evidence of dogs being able to sniff out cancer and warn their owners. One published report describes how a dog discovered a cancerous skin tumor on her owner’s leg. Other research supports the theory that dogs have the ability to smell cancer. Some dogs have been trained to detect cancer. But the real promise may be in learning how dogs can do this and possibly developing medical technology to do the same.

Looking Toward the Future
Dogs may never be used in the doctor's office. However, studying how animals can detect diseases in humans could lead to future advancements in medicine and medical technology. For instance, by learning about the ways dogs smell a seizure or cancer cells, we can develop technologies to detect those same molecules. Medical “sniffing machines” have already been developed and are providing insight into the smells of disease for disease detection.

The Epilepsy Foundation

National Cancer Institute

Epilepsy Canada

Brown SW, Strong V. The use of seizure-alert dogs. Seizure. 2001;10:39-41

Can dogs smell cancer. InSitu Foundation website. Available at: Accessed April 4, 2014.

Seizure dogs. The Epilepsy Foundation website. Available at: Accessed April 4, 2014.

Strong V, Brown SW, Walker R. Seizure-alert dogs—fact or fiction? Seizure. 1999;8:62-65.

What is a seizure alert dog? Pet Partners website. Available at: Accessed April 4, 2014.

Williams H, Pembroke A. Sniffer dogs in the melanoma clinic? Lancet. 1989;1(8640):734.

Last Reviewed April 2014

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