How does a dog react when it smells cancer?

When a dog smells cancer, it will sniff crazily, spin in circles, or make some strange movements. Not all dogs can sniff out cancer. Those who can have a fixed response to sniffing out cancer are also professionally trained dogs. If a dog has some strange reactions due to smelling the smell of its owner, it does not necessarily mean that it is cancer. It may be that the owner has a smell that attracts it.
Relevant research shows that dogs can smell the smell of cancer. Dogs’ noses are very sensitive, and even dogs with a dull sense of smell have a sense of smell that is 40-60 times that of humans. Certain odors on a sick person may change, so it is normal for dogs to smell them.