Periodontal disease affects 85% of dogs and cats over three years of age. In some breeds, the incidence is almost 100%. Periodontal disease is caused by a combination of plaque buildup and the individual body’s reaction to it. It results in progressive bone loss around the teeth. The bone loss can cause tooth loss, oronasal fistula (loss of the tissue separating the oral from the nasal cavity), and pathologic fracture of the jaw. Daily tooth brushing and annual professional dental cleanings are the best way to prevent periodontal disease. To find home dental care products that have been proven to be effective, see the Veterinary Oral Health Council website.