At seven weeks a puppy is able to transmit adult brain waves.
Growth hormones circulate only during sleep.
A dogs sense of smell is 100 times better than ours. The scent of another dog on the ground can tell them what species it is, it's state of health, and which direction it was going. The part of the brain used to develop the information obtained from scent is larger and better developed than ours.
Dogs are more sensitive to sound than us. Sound only just heard by us at a certain distance, can be heard by dogs up to four times away.
Dogs are not colour blind, but see colour less well than we do, they can be better than us in dim and night conditions.
Dogs can hear ultra sonic sounds we cannot hear.
Dogs have evolved from wolves. All breeds of domestic dogs have brain cases approximately the same size. The difference between a Great Dane and a Chihuahua is purely one of size and shape, which has been man made.
