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.
1 The Elderly Waiver (EW) program is a federal Medicaid waiver program that funds home and community-based services for people age 65 and older who are eligible for Medical Assistance (MA), require the level of care provided in a nursing home, and choose to live in the community.