The average lifespan of cats is longer than that of dogs. With good veterinary care, an indoor lifestyle, cooperative genes and a pinch of luck, cats can live to 20 years or more. Aging, however, brings with it both physical and behavioral changes which, if ignored, may challenge even the most well-meaning of human companions.
As animals grow old, their bodies change internally as well as externally. Almost all body systems are affected by aging. Lifelong activity leads to joint inflammation or osteoarthritis, which can stiffen and slow cats just as it does humans. Important physiological functions taken for granted over the course of a decade may start to slow or malfunction. Kidney disease is a common affliction of old cats, as is hyperthyroidism (an oversecretion of thyroid hormone due to abnormalities of the thyroid gland). Each of the senses eventually deteriorates, leading to impaired vision, hearing, taste and smell (which may, in turn, result in decreased appetite).
While the physiological changes of older cats can often be detected through blood and urine analyses and other quantitative tests, behavioral changes may be difficult to measure. The brain is paradoxically both the most complicated and the most poorly understood of all body systems. Like any other part of the body, it is susceptible to the long-term deterioration of aging. Recent recognition of cognitive dysfunction in old dogs and cats has led to an increased understanding of this surprisingly common problem. Cats, like dogs, people and other animals, begin to show some degree of memory loss and disorientation as they grow old. Although there are individual differences, elderly cats may seem confused and can show that confusion or cognitive impairment in specific ways. Many cats, for example, will begin to urinate or defecate outside the litter box. They may jump off their owners
