Veterinarians are guessing at this caramel-colored horse's name and age, for now. One thing they know for sure is her weight: 835 pounds.

She ought to be between 1,000 and 1,200 pounds, her caregivers say. Those couple hundred pounds would fill out strange sunken areas of her frame. The spaces between her ribs. The deep crevasses of her neck. The valleys along her pelvic bones.

The mare, nicknamed IRS, is one of 10 horses seized from an East Bethel farm this week "under probable cause that they're being neglected to the extent that it jeopardizes their health and welfare," said Keith Streff, senior humane investigator of the Animal Humane Society. The horses are recuperating at the Large Animal Hospital on the University of Minnesota's St. Paul campus.

Streff alleges that the farm's owner, Lowell Friday, has been mistreating his animals and that recent complaints were just the latest in a string of violations.

Friday did not return phone calls, but has denied to other media that he cares for his horses improperly.

A horse's heft is judged on a nine-point scale. A 6 or a 7 is ideal, said Dr. Anna Firshman, an assistant clinical professor of large animal medicine. A 1, 2 or 3 -- the scores these 10 horses have registered -- translates to "poor, very thin or thin."

IRS has a swollen belly from parasites, not food, Firshman said. "Parasites can cause chronic damage to the gut," she noted, "and the older horses will have a harder time putting on weight."

Firshman looked into IRS' gigantic eyes, which had turned hesitantly toward her.

"She's quite old."

The staff at the U's Veterinary Medical Center immediately fed the horses, but not too much. They portion the hay to prevent "refeeding syndrome," which could harm or kill them.

So every other hour, the horses are given a chunk of a hay bale -- and after a day or two, the chunks get bigger.

"You look for reasons for them to have the weight loss, and then you feed them and see if they put weight on," Firshman said. It's too early, she said, to judge whether these 10 have gained weight, but she expects them to.

Staff members mark off meals on a checklist at each stall. Categories include temperature, pulse, respiration, water, attitude and faces.

Some crouch in the back of their stalls. Others, like Black Magic, nudge staffers' pockets in search of food.

"Every time we go past, it's, 'Hi, how are you doing? Can I come out? What do you have for me?'" said Sheryl Ferguson, manager of the Large Animal Hospital. "I think he's going to be a gorgeous horse with some meat on his bones."

Jenna Ross • 612-673-7168