Whats that title

I am looking for the title of old cartoon (apporx. 80's) about talking dogs. I think about particular full length cartoon (90 min.). The plot is about a special bone which is in some kind of museum. Thanks to this bone, dogs can talk and communicate with people. Some bad girl (her dog and uncle?) wants to steal it so dogs will stop communicating with people. It was really cool and watched it every now and then when was a child. Help me, please! THX!