Myers said he still was investigating the case and was awaiting the medical findings of veterinarian Christine F. Bridges to determine how long the animals might have been malnourished.
O'Brien could not be reached for comment Monday.
Bridges, who had examined every horse by Monday evening, said the most serious problem among all of the horses was "severe" malnourishment. The heart rates of almost all of the horses was elevated, if not double what it should have been, because they were becoming anemic, she said.
A 3-year-old chestnut gelding thoroughbred, which appeared to be a picture of health 60 days earlier, might ultimately have to be put down, according to Myers, who obtained a July 13 photograph of the animal.
On Saturday, the horse was exhibiting signs of organ failure because of starvation, Bridges said.
The horse's ribs were noticeable, and it also had bite marks on its back and neck from other horses. The bite marks are indicative of a struggle for food among the horses, according to Bridges.
Beginning about 10:30 a.m. Saturday, the horses were moved with the help of Berkeley County Animal Control officers and volunteers from Hidden Meadows to a nearby farm field the county leases for such situations.
Because of the number of horses seized, Laurie and Dudley Webber and Donna McMahan, who lease the remaining part of the farm plot, agreed to move their horses and goats to provide more room.
The most vulnerable horses, including a pregnant pony, were segregated into their own pens in or near the barn.
In addition to help from about 25 volunteers over the last few days, inmates from Eastern Regional Jail taking part in a trustee program also assisted, Myers said.
The horses are available for adoption beginning Tuesday, Myers said.
"We have enough of our own already," Laurie Webber said when asked if she was interested in adopting the horses. "But we're certainly able to help and foster (them)."
Individuals interested in adopting the horses must make an appointment through the Berkeley County Animal Control office, Myers said.
In the meantime, Myers said the county still is in need of horse-quality hay and grain.
"The expense to the county here is going to be tremendous," Myers said.
The Charles Town Horsemen's Benevolent & Protective Association, which has been working to support horse owners and trainers who lost horses in Labor Day weekend barn fires, arranged to deliver some hay for the horses, Myers said.
Anyone interested in adopting a horse or donating food for the animals can contact Animal Control at 304-263-4729.