pennhip will "certify" them at 16 weeks I believe ? the usefulness of the information , imo , is less than what they lead folks to believe , but I think it is still useful …even an x-ray at 7 months is useful information ... I've x-rayed a lot of dog , I honestly cannot remember ever being surprised at what I found out …….. not saying I could grade them by raising them and watching them , hip dysplasia can be a lot of traits that do not affect a dog , at least until they are old ….. I have been somewhat surprised how good a dog was , but never how bad one was , mainly because the breed of dogs I keep have on average pretty poor hip conformation ……. at 6-7 months there will be signs if a dog is going to be functionally dysplastic as a young to mid aged adult …….. I've not seen 6-7 month old dogs with muscular solid straight rears , good rear drive that they used , and symmetrical proper movement break down in their lifetimes ………..