KnowHow team explains: Cats have been much more recently domesticated than dogs and have been subjected to human breeding efforts for at most a few centuries, in contrast to the thousands of years of breeding that have produced hundreds of variants of the wolf.

There is no reason to assume that selective breeding and crossbreeding cannot produce more varied models of cats, and at least one unusually shaped breed, the Munchkin — a healthy cat with very short legs, has already emerged. However, the cat belongs to a basically natural species. Most cats choose their own mates, so the system of wild genes that offers protection against differences from the norm is still strongly at work.

Like humans, most cats end up with the same body plan as others. If an unusual mutation shows up, like the one that produced the Munchkin, it usually averages out with interbreeding and disappears in a few generations unless people keep the oddly shaped cats separate from the general population. As for size, some breeds, like Maine Coon cats, are much larger than others, and their breeders proudly perpetuate the difference. The difference, however, is only a few pounds, not like that between the Chihuahua and the Great Dane, and it is likely that the overall feline gene pool does not have a range of size possibilities as great as that of dogs.