Give them Shelter
If people want a cat or a dog, there are usually plenty available at local shelters. Stores in malls like The Animal Zone in the Great Northern Mall are often a source of problems for pets and owners alike. They sell sick animals to unwary buyers, sticking them with the vet bills in the end, or worse news for the pets. One dog in the aforelinked story was removed because it was underweight - this is just inexcusable.
If you're in doubt about shelter pets, you shouldn't be - medical problems are usually treated, and adopters are informed of any conditions. M_ adopted Conner in 1999 from the Berea Animal Shelter, and he's still our gray, unemployed, furry, sleepy friend to this day.