The question today is, what can dogs learn about you by smell? Dogs can smell you, they can smell your urine and they can smell other odors coming from your body. A dog is capable of detecting cancer, and other illnesses just by smelling a person. They can even detect if a person is going to have a seizure. A lot of people think a dog smells intensity, but it is more of a variety of smells they can distinguish at one time than the levels. Their nose is designed to separate the odors more than we can.