1470. The aggressive biting 3-year-old Corgi

A man brought in a 3-year-old male Corgi. "He bit my mother's hand," he said. "He jumped onto the sofa to get patted on his head as my mother used to do earlier but she was watching TV and so he just bit her hand. I want him neutered."

"Is she badly injured?" I asked as this Corgi has considerable strength and size.
"A big tear in her hand."
"Has he bitten other people?" I asked.
"The maid and snapped at my friend who wanted to pat him 6 weeks ago. Is it because my female Shih Tzu is on heat? I asked my children not to touch him as he growls at them. He only allows me to touch him"
"In theory, this dog should be put to sleep," I wanted to examine his mucous membranes as he was muzzled and put on the examination table. He growled, turned around and snapped at me. The man was the only one he does not bite.

"Why didn't you neuter him when he was younger at 6 months?" I asked.
"I don't like the idea. Besides, he does not bite till the last 2 months. Why?"

"He is a one-man dog. He had bad experiences of people or children pulling his tail or beating him when he was a puppy at around 2-3 months of age. So he does not like children."
"I give him a second chance. My mum visits me and does not stay for long and so I don't want to euthanase him."

What is the solution to stop him from biting people?
"Neutering may not help as he has developed a habit of biting people when touched. His canine teeth are strong and sharp and may tear the flesh of another person he bites."

Is there a solution to prevent an older dog from biting people?