I don't give mine ice cream, but I do give them the occasional piece of frozen juice bars, and I do give them the occasional licks of orange/rainbow sherbert.
Sherbert doesn't have the lactose in it. It is, however, high in sugar. So, an occasional taster spoon on hot days is about the most we go...
We also freeze juice on a popsicle stick in an ice cube tray, and give them those as well... Those are outside in the tree things, to save the drippy sticky messes.
Mine get very limited amounts of cheese. It's an occasional treat. Not an every day thing.