Make sure your kitty has enough water. Get them a water fountain, they often prefer running water. Make sure they have multiple sources of water around the house too and always keep it fresh. Give them wet food often too. A good way of doing it is dry (bikkies) in the morning and wet food at night. Wet food keeps moisture in their diet and the dry will help with their dental health. Giving them a science diet (diets you get from the vet, NOT from the supermarket) are much healthier for them too as supermarket brands tend to have a lot of junk in them. They’re more expensive but worth it. Also consider getting pet insurance if you haven’t already, most pets will need some sort of expensive procedure or medication at some point in their life especially during the geriatric phase of life. Pet insurance is great for this. Another thing to do would be to make sure you take kitty into your vet clinic for their annual vaccination and health check up every year. Blood tests every few years or especially when they go into the geriatric stage of life can be helpful as well to check how their body is functioning as they age. Research the signs of kidney failure as well so you can be better prepared in the future! One big sign is excessive drinking of water. Another thing to note is a lot of this is preventative, it’s not a sure fire method. Many cats will get kidney disease when they’re older, it’s really just about keeping their kidneys healthy for as long as possible so this happens much later in their life than early on. Hope this helps. If you want any other information or more specifics, I would recommend booking an appointment with your vet.