A Saco dog breeder lost two pregnant German shepherds when fire swept through a large barn at her farm Thursday.

Robert Martin, deputy chief of the Saco Fire Department, said the fire was discovered by the owner of Timber Ridge Farm, Doreen Metcalf, when she opened a door to the barn at 221 Simpson Road shortly after 9 a.m.

Metcalf boards, trains and breeds dogs at the farm, and also boards horses there. The barn that caught fire was used exclusively for dogs, Martin said.

Metcalf managed to get all the dogs out of one end of the barn after discovering the fire, Martin said, and also freed dogs from an outside enclosure attached to the barn, but the smoke and flames at the other end of the barn were too thick for her to get through. He said that’s where the two dogs, one of them in the process of giving birth, died.

The loss of the dogs comes four months after another of Metcalf’s dogs, a 5-year-old female German shepherd named Uhdelle, was hit and killed by a car.

Uhdelle had wandered away while Metcalf was horseback riding on a trail with several of her dogs, and police believe someone picked up the dog and set her loose in Gray, where she was struck by a car.

Metcalf offered a reward for information leading to the conviction of whoever took Uhdelle, and police in Saco and neighboring Buxton asked for the public’s help, but there have been no arrests in the case, police said.

Martin said firefighters from seven neighboring towns helped Saco firefighters try to put out the flames Thursday, but the barn’s roof collapsed and the structure was destroyed. He said firefighters had to shuttle water from sources about a mile away to try to douse the flames. Crews were on the scene until after 2 p.m., he said.

Metcalf told him that she has insurance and should be able to rebuild, Martin said.

He said fire officials believe they know the source of the fire, but are withholding that information until they complete an investigation, a process expected to take only a couple of days. The fire is not considered suspicious, he said.

No one was injured, Martin said.