Watch: 'A cheetah's best friend' - Puppy waits by the side of new cheetah best friend during leg operation

Ruuxa the cheetah cub and Raina the puppy met after Ruuxa's mother rejected her and have been inseparable ever since

Ruuxa the cheetah after his surgery with best friend Raina the puppy (ITN)

A cheetah cub is recovering from surgery in San Diego Zoo today after being supported throughout the procedure by his new unlikely best friend, a Rhodesian ridgeback puppy.

In one of the strangest friendships to come out of the animal kingdom, Raina the female Rhodesian ridgeback puppy sat nervously throughout Ruuxa the cheetah cub’s surgery, in an operation to correct a condition that caused Ruuxa’s legs to bow.

According to park officials, Raina watched intently as Ruuxa went under the knife and then waited for hours by the cheetah’s side until he came out of sedation.

"Raina appeared very concerned about Ruuxa when she saw he was sleeping and she couldn't wake him," Susie Ekard, an animal training manager at the Safari Park, told CBS. "She licked him and nuzzled him, and when he awoke, she lay with him and seemed very content to know her cheetah was okay."

According to those at the park, Ruuxa and Raina have been inseparable since they were paired as companions three months ago.

Ruuxa was born in the zoo in June but was made an orphan after her mother rejected her just days later.

It was decided then that Raina would be chosen as a companion for Ruuxa and ever since the pair have rarely left each other’s sides.

What makes this partnership even more strange is that Rhodesian ridgeback, a breed developed in what is now Zimbabwe, was once used to help farmers hunt down and kill lions that attacked their livestock.

The surgery Ruuxa underwent was to correct a defective growth plate in her ulna, a problem that caused a bowing of the legs and could potentially have an impact on the cheetah’s ability to walk in later life.

Jeff Zuba, a senior veterinarian who helped with the procedure said: "This is a condition occasionally seen in domestic dogs and, if not treated, can cause pain and problems with the animal's ability to walk later in life."

Doctors were successful in correcting Ruuxa’s leg and it is expected that she will now make a full recovery.