Older cats get more sensitive to noise, are not as playful and are in general much less active. It does not mean that you should leave him alone and let him sleep all day!
An old cat still likes to interact with his humans: You should groom him, play with him without any excess of course, on a daily basis.
An aged cat's metabolism slows down and he will gain weight. Older cats become lethargic due to over weight. So, try to monitor his diet and keep him active if you can. Older cats fed dry kibble tend to have cleaner teeth, less gum disease and a better weight. If you switch food, make sure to introduce the new one slowly as it could upset your cat digestive system.
He will probably have muscle, joint, neck pain and arthritis. Feeding him from an elevated cat feeder will help with the pain, and it will be easier for him to reach the food itself as it will be elevated.
Keep water accessible at all time, as he needs to be kept hydrated.
Make sure that your cat has a warm comfortable bed on which to rest, as he will be spending more time sleeping. Ensure that he doesn't sleep on a cold floor. The cold will seep into his bones, which may be arthritic and will cause him pain and discomfort.
If possible, have a cat bed slightly raised off the floor, but not too high so he does not need to jump up to get on it.
Mobility is an important issue for older cats. You should have all he needs on the floor rather than on counters and furniture: His cat feeder or cat bowls, cat bed, and litter box should all be kept on the floor for easy access.
Keep his toys in a special place like a pet toy box so he knows where to find them when he feels like playing with them.
And more importantly, take him to the veterinarian for regular check-ups, and especially if his eating habits or behavior changes drastically.
It is not unusual for older cats older to show signs of confusion, disorientation, get trapped in corners, spacey, aimless wandering, less playful, more irritable as he gets older. In some cases, the problem is the brain itself. This is cognitive dysfunction syndrome or, simply, senility. A form of feline Alzheimer's disease.
With proper care, many cats live to be 15 to 18, even older.
