Abnormal or unpleasant odors may be caused by diseased or necrotic tissue in the respiratory or upper gastrointestinal tracts, including mouth and nasal cavity. Diseased teeth are a common cause in dogs and cats. In addition, certain metabolic diseases may produce distinctive breath odor, e.g. ketoacidosis, uremia.
Practically elderly is a person who needs special consideration due to advanced age. Which can happen in late 50s or in late 80s. If he or she can punch your lights out for calling them elderly, and you cannot run from them either, they possibly aren't.
Quick Answer. According to news outlets like NPR, the New York Times and Philadelphia Metro, someone between the ages of 69 and 71 is considered elderly. Technically, a person is considered elderly if he is past middle age. However, some people feel that the term elderly is used to describe someone who is feeble and unable to care for himself.