Kel I teach kindy at school and I always make a big deal about someones birthday at school. Most parents send in cup cakes or those mini donuts for the class and we sing happy birthday to the child. (WE have a couple of kids with nut allergies so parents always send a mini packet of those natural confectionary lollies for them so they are not left out)

I also let the birthday girl/boy sit at my desk all day (which they love) and they wear a special birthday badge. It depends on the teacher I guess but with younger kids I think most teachers make a big deal about it for them.