Season 4

Derrick heads to Colorado to build a custom prosthetic for Wesley, a two-year-old rescue dog born with a front limb deformity. Derrick hopes a new leg will help Wesley keep up with his adventurous family for years to come.

Derrick travels to Glendale, Kentucky to help out a cuddly raccoon named Boone, who needs a custom cart so he can freely move around his home at an animal sanctuary.

Derrick visits a family in New Jersey to help two rescues: Angus, a cat with multiple amputations; and Lux, a dog who lost his front leg. Derrick's devices will help Lux and Angus keep up with their family.

Derrick gives a dog named Watson the chance to walk with a full limb prosthesis. Derrick then heads to Connecticut to help Peaches the goat with a custom cart.

In Lancaster, Pennsylvania, Derrick meets the Hicks family and builds a custom prosthesis for their dog, Millie, who was born with a front limb deformity.

Derrick visits California to help a sheep named Timmy and his goat friend, Poppy. Timmy and Poppy share a stall and also share front leg mobility issues.

Derrick helps a pup named Rosie who is missing a paw and needs a custom prosthetic. Then, Derrick travels to Los Angeles to meet a chihuahua named Roo, who was born with two legs and needs a custom cart to help her keep up with her best friend, Chase.

Derrick travels to Sheridan, Illinois to help a camel named Moe. Due to his collapsed legs, Moe has been confined to his stall for four years and unable to go outside. For the first time, Derrick builds a set of braces for a 1500 pound camel.

Derrick helps a big dog named Bently with his back leg issues; Derrick then heads to Florida to help Ujwala and her foster dog Kala. Kala is a rescue from the streets of India who must learn to trust Derrick and the new prothesis.

Derrick and his wife, Kelly, travel to Thailand to visit Elephant Nature Park to help Mae Mai, an elephant with a painful dislocated knee. Derrick also helps a young bull elephant named Khun Dej and a bull named Mr. Cow.

Derrick and his wife, Kelly, travel to Thailand to visit Elephant Nature Park to help Mae Mai, an elephant with a painful dislocated knee. Derrick also helps a young bull elephant named Khun Dej who has an injured foot.

Derrick and his wife, Kelly, travel to Thailand to visit Elephant Nature Park to help Mae Mai, an elephant with a painful dislocated knee. Derrick also helps a young bull elephant named Khun Dej who has an injured foot.

Derrick travels to Thailand to help disabled elephants Mae Mai and Khun Dej.