I buddy of mine spent 5 years in Germany training dogs. The germans are real strict about dog training! He had a beagle he trained to retieve birds. The dog will track and chase (flush) anything you train it on. The retieving part he said took an hour or 2 after work every day for 35 days! And he is a pro! He is now convinced that any dog can be forced trained, but you need to be carful not to break your dogs spirit.