One evening recently, my husband and I happened to watch a BBC documentary on dogs detecting cancer. The program described some small studies and some experiences of dog owners. Most interesting to me was that clicker training was used to teach the dogs to detect cancer.
Here is how they did it in a study in the UK:
First, they showed a professional dog trainer teaching an exuberant dog to sit with the clicker. This was basic clicker training. The man clicked when the dog sat and then immediately gave her praise and a small tasty reward.
Next, they used an apparatus on the floor, essentially a box maybe a foot high and several yards long, with several small openings where the researchers could put things that the dogs could smell but not really get to. Food of some sort was put in only one of the several openings, and the dog was clicked and treated for sitting at that opening.
Once the dog had the idea, the study moved to a situation where a sample of urine in a plastic container was the thing the dog had to sit for. This urine was taken from a man with prostate cancer, and the other holes had nothing in them. Once the dog understood that, they added urine samples from men known not to have prostate cancer in the other holes, and again the dog was clicked and rewarded for sitting at the right opening — which it mostly did.
The dog might have been picking up cues from the trainer, so next they corrected for that. There were numbers on the wall for the openings and the trainer didn’t know which sample was the correct one. A research assistant who had placed the samples closed himself into the adjacent bathroom so the dog couldn’t see him. When the dog sat, the trainer immediately called out “three” or whatever the number was where the dog sat. If the assistant called back “correct,” then the trainer immediately clicked and treated. When the dog didn’t get it right, the trainer did nothing and the dog was free to sniff around some more.
Clicker training was so effective in getting the dogs to understand what the people wanted them to do. I loved it.
It was very exciting to watch the dogs getting things right, but sometimes they didn’t. This documentary had the date of 2005 on it, so research may have continued since then. It had been hard to get funding, though. In one research program in Florida, dogs were able to detect down to two parts per trillion of some samples. That was a different form of cancer; I don’t remember which.
The show had a real-time personal experience, where a woman had a lesion on her leg. One of her dogs paid it no attention, but her Miniature Pinscher wouldn’t leave it alone, and kept licking it and licking it. Finally the woman decided she might as well have it checked and went to a doctor. It turned out to be pre-cancerous and she had it taken care of.
I don’t think I will be clicker training LarryDog or Lola to sniff out cancer, but I must say that if any dog ever starts paying undue attention to something on my body, I will get me to a doctor! The program was called something like “Can Dogs Detect Cancer?” and is worth watching if you come across it.