Bella loves ice cubes and so does Brussels. I've dropped one every now and then by accident and they come rushing over to grab it...but they always get the "drop it" command.
I don't give them to them on purpose though, because I'm always afraid they'll bite it and a piece will break off and they'll choke or get cut.

I'm such a worry wart when it comes to my pets. Ice cubes are probably perfectly safe...but I know I've cut my mouth on them before.