We have a Border Collie that is OBSESSED about any ball...tennis, golf, pine cone
, whatever . We have to throw it a million times in a row. It is very annoying after awhile, especially when she barks (very loudly and piercing) if we don't play with her. It is truly an obsession and is a negative trait in her. When we have company over, we cannot let her have the ball because she will not let anyone have a minute to themselves. I saw a Dog Whisperer show about this also.