Has my dog been eating sardines and garbage? All jokes aside keeping your dog’s teeth brushed is important because good dental hygiene helps prevent plaque buildup, gum disease, and painful infections that can affect their overall health. Poor oral care can lead to bad breath, tooth loss, and even serious issues like heart, liver, or kidney problems caused by bacteria spreading from the mouth. Regular brushing keeps their teeth clean, their breath fresher, and supports a longer, healthier life.