Why does my dog sniff everything?
Dogs are known for their super keen sense of smell. Dogs are reported to have approximately 40 times more smell sensing cells in their nasal passages than we do. To that end, understanding your dog's responses to certain situations may be out of the question. With such a super sensitive sniffer, dogs rely on this sensory information far more than we do. Given that some dogs are now being trained to smell changes within the human body, we may never notice the odors our dogs react to.
For more information on understanding your dogs world, please read Understanding Your Dog Better