Can dogs really smell cancer?

Studies are preliminary and inconclusive.

Dogs (and cats) appear to be sensitive to scents that can imply illness or disease. After all, they have 100x the amount of receptors in their sinuses that humans have. I’ve noticed our family dogs were more partial to new people when those people were blood relatives. Somehow, there was some similarity in body odor that our dogs could identify. Dogs have demonstrated they have the capacity to recognize and respond to people with epilepsy and other problems. It is not inconceivable that they could recognize cancer. It just takes training and the necessary innate personality suitable to the profession.

The answer you are looking for is no, they cannot smell cancer. They are, however, as the previous poster indicated, sensitive to changes in body chemistry that would indicate illness. There are no indications, however, that they are able to distinguish cancer from other illnesses. It seems unlikely, as well, given cancer’s particular pathology.

Scientific studies indicate the previous poster is incorrect. Dogs can specifically detect cancers: http://news.nationalgeographic.com/news/2006/01/0112_060112_dog_cancer.html

@Marina, With all due respect, when you cite a National Geographic synopsis of a paper published in a journal called Integrative Cancer Therapies you lose a little bit of credibility. I’ve been involved in medical research for 15 years, and have never heard of this journal. I’m not even sure if the paper underwent peer review. I’ll read the actual paper tonight and get back to you regarding its scientific merits.

I train dogs to find lost people and human remains. There have been some case/control work with dogs who are given one petri dish with a type of cancer (bladder cancer if I recall) and five dishes with placebo tissue samples (i.e., no cancer cells present). The dog is trained to respond to the one with known cancer cells. The trainer changes up the placement of the known sample to ensure the dog is not hitting on the location rather than the scent.

There was an instance when the dog hit on a new sample of what was believed to be non-cancerous cells and rather than correct the dog, they rechecked the patient source of the sample to find that the dog was correct.

As my dog will find people underwater (because he has been trained on adipocere and decomposing human tissue underwater) as well as on land (training on all types of tissue and bone), I can’t tell you what part of the sample is stimulating him to respond (my nose doesn’t work as well as his).

So it is impossible to guess what element of the sample is causing the dogs to react, but there seems to be consistent reactions to the indicator sample using the same training methods we use for human remains detection.