What is a dog's strongest sense?

A dog's strongest sense is its sense of smell. Dogs have 20 times more scent receptors and devote 40 percent of their brain to their sense of smell. Their sense of smell can be more than 100 times more sensitive than humans.

Dogs are used for their scent tracking for hunting or police work. Some breeds of dogs can track scents even after a long time has passed. New ways for utilizing a dog's sense of smell, such as sniffing out cancer, are being developed. They have a special scent receptacle called a vomeronasal organ, which can sense changes in body chemicals and hormones.