Hopefully he will stay there for life, and not be moved on again.
That is good news.
There is a dog rescue in Australia that took dogs from a terrible hoarder/breeder situation.
One was a young male whippet who had never been out of his crate in a shed.
He went to an 'experienced' new home, as an only dog...The adopter just couldn't get him to trust humans in any way shape or form.
He hated living indoors with her, was afraid of outdoors...she had him for over a year.
He just about tolerated living in a box kennel on her verandah - he hated being touched, wouldn't go out for walks as it was too scary.
Vet said euthanasia would be the best thing for him as he was so fearful {shaking and trembling} of everything {but not aggressive}
She contacted the dog rescue where he came from, as she found it very hard to deal with his behaviour {basically she wanted a loving pet} and they found someone who had taken an older Female Whippet who had been in the same hoarding/breeder place.
They introduced the two Whippets at the shy dog's place and it was like magic.
They wondered if they were mother and son..{Quite possible}
Suffice to say the male Whippet now lives with the older female Whippet - he still distrusts humans, but that doesn't matter- he lives with this older Whippet who is human friendly, and he now comes indoors to the new owner's home where he takes comfort from the older Whippet.
Early socialisation is so important - one of the worst things is for a dog to have spent it's formative months/years in an unstimulating environment- it will find everything terrifying, even outdoors.
{Pic of a young puppy being carried about to get them used to the sights and sounds of its environment.. see how interested the pup is! - not at all fearful.}