Earlier this year, a boxer puppy named Duncan was born in the Seattle area with deformed back legs. When he was 12 weeks old, both of his back legs were amputated.

While Duncan's owners have a custom WHEELCHAIR for him, he doesn't need it  In the month that have passed since his surgery, he's learned to run on JUST his two front legs, and JUST as fast as 4-legged dogs.

Incredible video...