An endurance horse in America is defying the odds and recovering from yet more surgery after being impaled by a tree branch earlier this year.

Owner Gary Sanderson found Galapago Amigo with a two-inch wide three-foot long tree limb stuck deep in his left side on 17 January.

But no one knows how the branch became lodged in the horse.

A vet suggested Amigo be euthanised but Gary insisted he was taken to a veterinary hospital.

The horse is now in recovery at the University of Tennessee College of Veterinary Medicine.

Dr Nicholas Frank at the veterinary hospital told local press: “We’d seen various sorts of chest injuries, but nothing this dramatic. The other surprising thing was he was standing looking remarkably good considering what was going on with his chest.”

Amigo who is ranked with the American Endurance Riding Conference, broke two ribs in the accident.

Owner Gary told local press: “His gums were blue, and he had the smell of death on him. I’ve been an emotional wreck ever since.”

Amigo has undergone several operations and has nearly died several times.

During the first operation to remove the tree limb his left lung collapsed, followed by his right. They were both successfully re-inflated.

But last week during more surgery, to treat an infection, both his lungs collapsed at the same time, and he was almost put down.

He recovered though still has the infection.

“We shouldn’t underestimate this horse,” Dr Frank added. “He has a tremendous stamina and will to live. He’s pulled at the heartstrings of most of us here.

“It’s difficult to predict the outcome. You never know when a patient turns the corner, but we have made a tremendous amount of progress when he had less than a fiver percent chance to live.”

Amigo has reportedly received 6,000 letters of support from around the world. He also has nearly 6,500 fans on Facebook, who are helping to raise funds to assist with the $22,000 vet bill.

An update on Facebook last night read: “Good evening everyone! Amigo has had a really good day. He’s eating well and begging for treats. When you walk around the corner (leaving him alone) he whinnies for you to come back. (I think he just wants company). His vitals are all good and he is super alert.”