My prevous dog was a rescue Cavalier King Charles Spaniel. He was a sweetheart, but he did eventually pass away of congestive heart failure at the age of 12.
At the animal hospital, there was a 5 year old pug that was dying of congestive heart failure.
The vet said that Cavailer breeders were just breeding heart disease. That's a shame because Cavailers are very loving dogs.
My current dog is a rescue mutt - 1/2 long-haired Chihuahua, 1/8 Cocker Spaniel, remainder = terrier + miscellaneous. She was on PetFinder as a Cavalier mix puppy, but the DNA test was conslusive - anything but a Cavalier.
The last thing I wanted was a Chihuahua or a terrier. It was a reminder from God that He's in charge, not me. She is very loved and very loving. I've had to up my energy level to meet hers.
She is a funsized force of nature with phenomenal intelligence, dexterity, smell, hearing, and sight. I think there might be some Rat Terrier in there, because she would make for a great varmint hunting dog. She can see black cats on a cloudy, moonless night from a distance of 1/8 mile. She can easily spot a rabiit at a distance.
The Cavalier wouldn't take notice of rabbits until we were within a few feet. The Cavalier liked chasing birds, especially Canada Goose, and, once, four wild turkeys. I guess one of the things Cavaliers did back in England, was flush game birds from tall grass and low brush.
The Chihuahua mix doesn't have the Irritable Bowel Syndrome issue that the purebred Cavalier had. No heart issues at 5 years old.
The thing about dog breeds and breeding - that has nothing to do with the dogs, it's peoples' doing. Breed standards came out of the eugenics movement of 1800s. The dogs themselves don't know, nor care, what breed they are. They are happy to love and be loved.
I try to be more like my dog every day. She's the best person I know.