Some cats, like some people, can go a lifetime without rigorous dental care without ill effects (other than disgusting everyone who smells their breath). However, this is the exception and not the rule. A little care can go a long way toward making your cat more appealing to be near as well as preventing significant dental problems. If you've paid attention to his teeth his entire life, you've done your pet a wonderful service. If you haven't, you have some catching up to do to ensure that dental problems don't make your cat unhappy. Bad teeth can lead to pain while eating. In addition, some people believe periodontal disease can lead to other ill effects when bacteria (causing disease in the mouth) enters the bloodstream and causes infection in the kidneys and other organs.