Change diet for older chins?

[Teekachin]

My two girls are 10 and 11 years old. Both are very healthy and active, just as they always have been - okay, Trinity may be a little more persnickety, but she's always been rather particular about things :cute: But other than that, all is great. When they got a check up a bit ago, the vet said she considers them middle aged and that I may want to decrease the calcium in their diet. Is there anything else that I should be doing, changing, or watching out for?

Thanks for any incites or advice you can offer.