My favrite animal
The dog is a mammal with sharp teeth, an excellent sense of smell, and a fine sense of hearing. Each of its four legs ends in a foot, or paw, with five toes. Each toe has a soft pad and a claw.
Smell is a dog's most prominent sense and the one that is the most different from ours. It has been estimated that a dog's sense of smell is 100,000 times more powerful than a human's. Scientists think that dogs have about 2 billion olfactory receptors—many, many more than our 40 million.Dogs have a keen sense of hearing. In fact, they are capable of hearing sounds four times further away than the human ear can discern. Their ears are also better designed to gather more available sound waves. They have 15 different muscles that move their ears in all directions. Plus they can move one ear at a time, independently of the other, to absorb even more information.
Dogs are usually pregnant for around 63 days On average, giving birth to an entire litter takes 3-12 hours from the start of contractions/straining. Exact timing varies, but most dogs give birth to their whole litter with 6 hours. The process should never take longer than 24 hours - any longer and the risk of a problem becomes very high.
Dogs are the most variable mammal on earth with around 450 globally recognized dog breeds.