My cat has normal "old cat" problems, so she's slightly special needs. She's in the beginning stages of renal failure. At 15-16 years old, I'm not too surprised, but sad nonetheless. I've had her since she was only weeks old when my brother brought her home from the woods. With her kidneys failing, she gets a special canned food diet for renal problems, antacids for the upset stomach caused by her body having a harder time processing food and water, and subcutaneous fluids. Right now, she only gets the fluids every 3-4 weeks because she has no trouble drinking enough water and passing it through. As things progress, she'll get it more often to maintain hydration.
The wind of heaven is that which blows between a horse's ears. ~Arabian Proverb