American Shorthair vs Himalayan

The 'all-American working cat' story implies a hardy, mixed-heritage constitution, but this is a closed pedigree bred like any other purebred, and Cornell's feline health center lists American Shorthair among the breeds with an elevated rate of hypertrophic cardiomyopathy — the same silent heart disease people specifically worry about in Maine Coons.

A Himalayan is a Persian with Siamese coloring, which means it inherits the Persian's flattened face and everything that comes with it — chronic breathing difficulty, constant eye tearing and staining, and, per veterinary surveys, roughly a one-in-three-to-one-in-two chance historically of carrying the dominant gene for polycystic kidney disease that will eventually cause kidney failure.