KIPU, Kaua'i — Ribs still showing and her spine a sharp ridge, a rescued mare delivered a healthy foal Monday at the Kaua'i Humane Society Shelter, just three weeks after the abandoned and severely malnourished animal was found in a Kalaheo coffee field.

"We've tested both of them and they're doing fine," said Humane Society director Becky Rhoades, a veterinarian. She said that if the mare had spent much more time in the wild, she probably would have aborted the baby horse and died herself.

"It's amazing that she had this foal."

Both Rhoades and consulting veterinarian Scott Sims noticed that the mare had a big belly, but neither tested for pregnancy. Both said they were suspicious she might be carrying a foal, but also considered ailments that could have caused it. Then on Monday morning, when Humane Officer Barb Kaauwai went out to feed the mare, she found the foal, which has been named B.K. in honor of Kaauwai.

In the three weeks since her rescue, the roan mare has regained about 100 pounds and is able to feed her colt, a frisky, green-eyed light chestnut. His eyes will turn brown like his mother's as he ages, Rhoades said.

She estimates the mare, who appears to be part quarter horse, is about 17 years old and has probably given birth before. She is an attentive mother, nickering when the colt walks too far away and curiously approaches a reporter.

The Humane Society first heard in early June that there might be a starving horse in the coffee fields, but whenever its wardens showed up, they couldn't find her. Finally, they did.

"A woman walking her dog near the Kalaheo coffee fields reported seeing the horse, but it was two weeks before we could find her," Rhoades said. "She was in tough shape."

The animal was lame in both front feet, starving and dehydrated. Rhoades estimated she had lost more than a quarter of her normal body weight, down from as much as 1,100 pounds to 800 pounds or less.

Rancher Bobby Ferreira helped haul the animal back to the society's new horse shelter at Kipu, and Sims cared for the horse.

"She was definitely pretty seriously starved down. Even if they're skinny, they can maintain a pregnancy," but many abort before birth, Sims said.

Rhoades said the mare, named Whinny for her vocalizations when shelter officials bring feed, appeared to have been around humans before, but she had two lame front feet, an infected tooth that needed removal and other teeth that were in bad shape, and there were signs she had received no recent veterinary care.

"I think she's had a really tough life," Rhoades said.

She appears to be getting better. Delivering the foal should take some pressure off her feet, and a horse shower will build pads for her hooves to further ease her discomfort.

This is the 12th horse that has been found, apparently abandoned by its owners and left to die, since Rhoades arrived to take charge of the shelter in 2001.

Anyone claiming to be the owner likely will be cited with abandonment and possibly cruelty, Rhodes said.

The Kaua'i Humane Society will begin looking for someone to adopt both mother and colt in about a month.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.