11 Small Dog SuperheroesPint-sized power! From Chihuahuas to Maltipoos, these pups don't let size keep them from packing a big punch

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MAX THE YORKIE

For wheelchair-bound Tristan, 6, his 1.2-lb. Yorkshire terrier puppy Max was his world. So when the dog came down with congestive heart failure, a team of doctors stepped up, including a cardiac surgeon who saved the dog – and the boy's spirit.