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.
Assisted living residents are usually seniors who have had a slight decline in health in some way and need assistance performing one or more activities of daily living (ADLs). Seniors who would like to live in a social environment with little responsibilities and a place where care is easily accessible whenever the senior may need it are the type of seniors you will find in an assisted living community.