There are some conditions do not manifest until the latter years of life, eg hyperthyroidism Hyperthyroidism .
Weakening of musculature can occur, eg megacolon Megacolon and overgrowth of claws.
There may be a reduction in efficacy of the immune system. Certain infectious diseases grow in incidence in older age compared to middle age, eg FIP Feline infectious peritonitis .
There are also classes of disease that are less likely during old age, eg trauma.
Reduced interest in activity may be considered normal but care must be taken in distinguishing this from diseases that would benefit from medical intervention, eg degenerative joint disease Arthritis: osteoarthritis .
Reduced activity combined with reduced metabolic rate may lead to a body weight increase Obesity if the diet is not adjusted accordingly Dietary requirements: geriatrics . Although the increased incidence of disease seen in old age may often be associated with weight loss.
House training Indoor toileting may be forgotten due to senility Feline cognitive dysfunction syndrome , although other causes should be considered, eg musculoskeletal disease or constipation. Increasing accessibility to the outside and to litter trays may be helpful.
Pain from insidious conditions may show as behavior changes, eg depression or aggression Aggression: overview .
Hematology and biochemistry should be carried out to assess the general condition of the patient before any major procedure is performed.
Extra routine investigations are often recommended for geriatric patients, eg routine examinations at a higher frequency and screening tests such as: hematology, biochemistry, urinalysis, endocrine tests and blood pressure measurement.
There is an increased risk of side effects from medications in old age due to the interaction of factors listed above. Procedure such as routine laboratory work can help to lower this risk as can more frequent monitoring.
Reduced activity, decreased metabolic rate, lowered protein requirements, decreased efficiency of utilization of food and various age-related illnesses mean there is often a benefit in special diets Dietary requirements: geriatrics .
Increasing accessibility is important, both for food and water.
Increasing the amount of wet food compared to dry may be helpful to maintain good hydration.