"Do not give fruits to the puppies!"
Translation:Nu le da fructe cățeilor!
Hm... ”nu dați fructe” has to be accepted. These imperative sentences are more likely to be at the second person plural in Romanian, like in public places, at work, etc., unless you are very intimate with your interlocutor [ex: in the zoo, is always ”nu hrăniți animalele” (”do not feed the animals”), using it at singular would be very impolite].
îi is sometimes dative and sometime accusative. îi is accusative for third person masculine plural (i.e. masculine "them"). îi is also dative for masculine and feminine singular third person (i.e. to "him" or to "her") . Make sure you review the pronoun tables in a good grammar book or Internet site.