A 1-month-old was attacked and seriously injured by a puppy while he slept with his mother Saturday.

The baby suffered “substantial damage” to his genitals while he lay in bed with his mother from an attack by the family’s 6-month-old Cairn terrier and poodle mix, police said.

The mother told police she went to bed with the child after returning from work about 6 a.m. and was awoken about 1 p.m. by her 5-year-old. When she awoke, she noticed the baby had been moved and his diaper was missing. She then saw he had blood on him and rushed him to St. Joseph Hospital, the report said.

The baby’s injuries required transfer to Lutheran Hospital, where he underwent corrective surgery. He is expected to survive, but police did not know whether the injuries caused permanent damage. An updated condition from the hospital was not available Monday, police spokesman Michael Joyner said.

Investigators believe nothing from the attack suggests neglect was to blame for the child’s injuries and no charges are likely, Joyner said.

The dog was relinquished by its owner and was euthanized, said Belinda Lewis, director of Fort Wayne Animal Care & Control. Its remains are being sent to Indianapolis for rabies testing in the hopes that the baby will not have to go through rabies treatment, she said.

Peggy Bender, community relations and education specialist for Animal Care & Control, said it is important for families with young children to always supervise animals.

“As soon as you are aware a baby is going to join the family, you need to be thinking in terms of preparation and supervision,” Bender said.

She recommends preparing dogs with obedience training, not only so the animal learns to obey but also so a professional can evaluate its behavior.

They should also be “crate trained” so dogs become accustomed to being in a crate when they cannot be actively supervised, Bender said.

“It is just critical to always supervise young children around pets,” she said. “Never leave an infant baby in a room where a dog has access to it if you are not actively supervising.”

mhubartt@jg.netAnne Gregory of The Journal Gazette contributed to this story.