These problems can cause weight loss, chronic pain, decrease in their quality of life and lead to secondary diseases such as heart, kidney or liver diseases. Even with such long-term health concerns, your pet could have severe dental health problems, and with out careful monitoring, could go completely unnoticed. In as little as three years of age, dogs and cats can form cavities, get tooth root infections, have infections of the gums (periodontal disease) and have teeth weakened.