Would a dog be depressed if suddenly dropped off at a different home after being loved and spoiled for years?

Or would it get over it relatlively quickly because of it's brain compacity?

It would be depressed and confused and try to find a way out to get back to its former home.FYI: capacity, not compacity

For a little while, maybe, but dogs are pretty resilient creatures. They'll adjust to new circumstances fairly quickly.

My parents got a Pug from someone that had him for awhile. It takes a couple day for them to get use to the place but after that he will love his new owners just as much as the old ones.

They will be a little lonely and will of course miss the old home but, dogs are very easy going animals and will adjust easy! As long as the other family is loving and caring just as the previous owners were.

Yes, dogs and cats sort of rely on their routine. They get used to their people and the other pets in the house and when big changes are made it's confusing to them. I expect the dog would be unhappy though I can't say that it would be depression. I had two cats for many years, one of them died and the other one looked all over for him ... seems like it was forever but I think it was really for a month or two. I felt sorry for her, cause I missed him, too.