Mastiff mix Memphis the dog using her nose for nose work and loving it. Dogs have an incredibly acute sense of smell compared to humans. The part of a dog's brain responsible for processing olfactory information is up to 40 times larger than the same part in a human brain. This means that dogs have a much greater ability to distinguish and process different scents. Dogs have around 300 million olfactory receptors in their noses, while humans only have around 6 million. This a