Breeders breed dogs for “breed characteristics” which may not be in a dog’s best interest:
1. A short snout—nose—in a dog means respiratory problems: bulldogs, pugs (yuck!) pekinese etc. Demi snored something chronic

2. A long spine as in sausage dogs better referred to as the dachshund leads to spinal problems
3. Very big dogs—dobermann, Irish Woldhound, German shepherd, Great Dane, Giant Schnauzer—die fairly early, like 8yo, apparently because the heart has to do too much work pumping blood down and up the very long legs. Larger species of animals (compare elephant to a gnat) live longer than small species but the smaller the individual of a species is the longer is his life expectancy, e.g. small dogs can live to 18, even 20 years old, not so a Great Dane.
As well as problems like that and despite inbreeding not being allowed/recommended a pure breed has much less genetic heritage to draw on. For example, my chihuahua Tiffany, a purebred dog (bottom teeth undershot so not suitable for breeding/showing) was blind by age 10. Demi, a cross between a Maltese and a Jack Russell, did not get cataracts until she was 13 and still had pretty good eyesight when we had to end her life. She may have been a mongrel—two crossbreed parents—but she really did look like a Maltese with definite Russell tan patches and the huge prey drive of a Russell.
So, if you just want a pet, a crossbreed or mongrel may be the best choice, and smaller rather than larger. This probably applies to cats, enough said. If you are hobbling along on a walking stick a Weimaraner, Dobermann, Rottweiler etc likely not the best choice—dogs need exercise and socialisation and the stimulus of new sights and scents. Walkies in other words. Even for a chihuahua, small dog but all dog.
Did you have a favorite pet animal, what breed was it (or discernable breed characters in mongrel etd) did it live long and any comments on the animal?
Having said all the above, there is a chance I may get the runt of a litter of Staffordshire terriers. Mother and father rather different in size, color, temperament etc so hopefully enough genetic heritage there, not 100% pure breed. Apparently they chew anything they can get their teeth onto—shoes etc. Any tips on preventing that?