It may sound odd to brush your dog's teeth, but it is actually necessary and should be part of your care routine with your dog. Poor oral hygiene can cause other health problems for your dog later down the road. Read on for some dos and don'ts of taking care of your dog's teeth. Dos Brush Weekly. Brush your dog's teeth each week. You don't have to brush your dog's teeth twice per day like you do your own; once per week should be plenty.