The claws of aging felines are often overgrown, thick, and brittle. In humans, aging changes in the brain contribute to a loss of memory and alterations in personality commonly referred to as senility. For various reasons, hearing loss is common in cats of advanced age. Aging is also accompanied by many changes in the eyes. However, several diseases especially those associated with high blood pressure can seriously and irreversibly impair a cat's ability to see.
Dental disease is extremely common in older cats and can hinder eating and cause significant pain.
Although many different diseases can cause a loss of appetite, in healthy senior cats, a decreased sense of smell may be partially responsible for a loss of interest in eating. However, the discomfort associated with dental disease is a more likely cause of reluctance to eat. Degenerative joint disease, or arthritis, is common in older cats. Although most arthritic cats don't become overtly lame, they may have difficulty gaining access to litter boxes and food and water dishes, particularly if they have to jump or climb stairs to get to them. Owners of older cats often notice changes in their cat's behavior, but consider these changes an inevitable and untreatable result of aging, and fail to report them to their veterinarian.