SAN DIEGO (CNS) - A middle-aged 90-pound African spurred tortoise nicknamed "Humpty" is continuing to recover Thursday following a surgery to fix his shell, which was severely cracked in several places when he fell from a 10- foot wall in Fallbrook, county officials said.

And though Humpty Dumpty from the nursery rhyme couldn't be put back together again after his great fall, the tortoise is expected to make a slow but full recovery -- not thanks to all the king's horses and men, but thanks to a local veterinarian specializing in reptile health.

Humpty, estimated to be about 35 to 40 years old, was discovered injured with his severely damaged shell on Sunday after a dog apparently chased him off a 10-foot retaining wall, County Animal Services Director Dan DeSousa said.

"He's a 90-pound tortoise, not a cat, so he didn't land on his feet," DeSousa said. "He instead landed on his back, on his shell."

The fall happened after the tortoise apparently escaped from his owner's yard -- the docile but powerful animal could have dug under a gate or broken through a fence, DeSousa said -- and was found in someone else's yard.

County Animal Services is caring for Humpty, and on Tuesday took him to a reptile specialist veterinarian for surgery.

"The specialist actually had to pry back parts of the shell, had to get in there with levers, to make sure it would fit back together as tight as possible," DeSousa said. "Fixing it was like a home-improvement project, with screws and other fasteners. Once it was in place, they covered the cracks with the material used to coat dentures, both to help it adhere and to prevent infection."

Like a human bone, the shell will heal over time, DeSousa said. But like anything with a tortoise, it's a slow process -- probably at least a year.

But for county officials, the decision to treat Humpty was an easy one, considering that African spurred tortoises, the largest mainland species, can live to about 70 years old, and Humpty could likely live another 35 to 40 years, if treated.

A Fallbrook resident contacted the county earlier this week claiming that Humpty might be his, DeSousa said. But when told that the tortoise's medical bills had already reached more than $4,000, that caller was no longer so sure about his ownership claim.

If the rightful owner does come forward, that person will have to pay the medical bills, DeSousa said. Otherwise, the shell surgery and any other costs associated with Humpty's recovery will come from the Spirit Veterinary Medical Fund, a pool of money that's been donated to the county to help animals just like Humpty that need extensive medical care.

On Wednesday, Animal Services posted several photographs of the recovering tortoise on its Facebook page. Humpty appeared to have a grin on his face, and one Facebook user noted that "he looks very pleased with himself."

"He is still on some very powerful pain medications," the county page responded, adding a grinning emoticon.

Humpty is recovering at a local county animal shelter, but if he goes unclaimed, will be sent to a facility specializing in tortoise rescues.