Does anyone here give their pups Greenies? If so, what size? The recommended size for a Maltese-sized dog is the Teenies but they are soooo small, I worry they could choke or something. Plus, the package says they should be six months old first or at a certain weight. Does anyone know why this is? I like that the Greenies help with teeth maintenance so I would like them to start snacking on them. But, of course, I want them to be safe and healthy so I will wait if that really is best. Insight?