Dogs brains and their senses

A brain of an average dog is less than 0.5% of the dogs body weight. The dog needs lots of nourishment to function, and gets more than 20% of blood pumped to the heart. Brain activity is predetermined by the "fixed wiring" of their genes.

A large part of the pre-wiring of the brain is scent/smell. But there are also the other senses: taste, touch, hearing and sight.