Caring for a Three Legged Dog or Cat

Petey is an abandoned put bull puppy who is 5 months old. We adopted him to be another member of the family along with with two black lab mixes and 5 cats in the household. He was mauled by the neighbors dog who attempted to pull him threw the fence causing severe injury to his left front leg . The leg was deemed so severely damaged that amputation was the only course. It's been three days now of pain for us to watch him however He thinks he's the strongest puppy in the world. He is getting around and going up and down stairs already . ( only 4 steps but wow!!! amazing. ) there really doesn't seem to be anything he can't do or wont try. I just hope that his attitude never changes and he continues to be the happy and healthy puppy we found and grew to love.