Brutus the Rottweiler is the second dog to ever walk on four prosthetic limbs, and he's doing great!

As a puppy, Brutus was left outside in freezing temperatures and got frostbite on all four paws. The breeder attempted to amputate the dog's feet himself, but Brutus was still in a lot of pain, according to Colorado State University James L. Voss Veterinary Teaching Hospital, where Brutus had his surgery.

After Brutus was rescued from the breeder, he went under the care of Laura Aqulina, who helped raise money for his prosthetic legs on a Go Fund Me page. The page raised more than $12,000 for Brutus.

Now that he has the prosthetic legs he needs, he is going through physical therapy to get comfortable using them.

"He's learning how to move with them on. Once he's mastered that, we will help him achieve higher-level functioning activities, like hiking and playing with other dogs," Sasha Foster, Colorado State University's certified canine rehabilitation therapist, told NBC News.

Watch him walk with his new legs in this Instagram video:

 Brutus doing some rehab exercises at @orthopets in his prosthetic paws. #prosthetics #rottweiler #disABLEDpets

A video posted by BetterPawsforBrutus (@betterpawsforbrutus) on Dec 3, 2014 at 3:41pm PST