Rescue dogs, from wherever, all come with some issue or other. Better shelters and rescue groups do try to screen individuals for common issues, like human/ child aggression, 'bad with cats', especially. My 'good with cats' turned out to 'not perfect' by any stretch. Good with specific house...
There are nice Chihuahuas. Really. Not many, but a few.
There are many polite bully type dogs, but most will be the terriers they are, and chase/ kill smaller critters. Mine are definitely like that!
Mary
Yes, genetics, and then training, to develop the desired behaviors. And then, some individuals never 'get it', and others do really well. And the jerks who do the fighting dog thing don't send their winners to the pound...
Mary
And very rare breed dogs do turn up in shelters! Our neighbor has a Russian Sheepdog, from a shelter. Rare, and a good thing, but their dog is very well managed, fortunately.
Mary
Talking about dogs who just aren't 'wired' right, can be of any breed. And I've met two killer golden retrievers, BTW. When we work with and have lots of dog experience, we all have stories like @Halfpasthen , involving dogs of many breeds. Usually there's more to the story, as in warning...
@Halfpasthen x2! And it's the 'feed him another cookie and he'll be better' approach; no boundaries, no corrections for bad behavior, just 'ain't he cute', until he really isn't.
Mary
Also, good breeders will do puppy testing, which helps select the right puppy for it's future purpose.
There are miserable wretches in every breed, and I have met young puppies who were little monsters, in several breeds. Dogs that would take an expert to manage, and no expert would buy such...
It's both genetics and management. Ideally meeting parents is good, because then you can avoid puppies who have difficult parents, especially the mother. Then, raising a nice puppy up right is always important, whatever the breed. Rewarding good behaviors and redirecting bad behaviors, from...
Did you know that there's a documented case of a Dachshund killing a person in the USA? And I met one who really tried, too. Sometimes it's not so much about size, as attitude!
Terriers in general were bred to be enthusiastic killers of smaller animals, and aren't usually suitable for...
I have two pit bull terriers right now, and have two others previously. All shelter dogs: one current dog was very abused as a youngster, came to the shelter with wounds, probably from a fighting dog situation.
All are very good with humans, and will kill any critter in their fenced back yard...