The foul odor you smell coming from your dog’s mouth is caused by an infection around the teeth. The most common cause of the infection in your dog’s mouth is periodontal disease, which affects over 75% of dogs over 2 years of age. The inflammation begins when bacteria set up house in the gums surrounding your pet’s teeth. Without tooth brushing, these bacteria flourish and, in combination with food particles, cause calculus deposition on the teeth. The vicious cycle begins: bacteria grow, creating inflammation, calculus deposits on the teeth, more bacteria grow, while the inflammation and calculus deposition continues. Left untreated, this inflammation progresses to periodontal disease. Periodontal disease describes an irreversible loss of the support tissues of the teeth. Destruction of the support tissues surrounding the teeth causes pain, deeper infections, and tooth loss. Unresolved infections caused by periodontal disease can spread beyond the oral cavity to include distant organs, such as the kidneys, liver, and heart. The goal of periodontal therapy is to restore oral health by cleaning the teeth before irreversible damage occurs. Dogs need their teeth cleaned regularly just as people do. Home dental care and regular teeth cleanings help maintain oral health to ensure a healthy, pain-free pet.