cat chasing!

Question
Please can you tell me how to stop my 6 month old german shepherd from continually harassing my cat! He chases the cat outside and inside, following the cat and trying to bite at his head.  It is not done in an aggressive way, he just wants to be playful!  The cat likes the puppy but warns him off with a tap on the nose - bit worried that he may scratch the dogs eyes or the cat will get hurt.
Help would be appreciated! thanks

Answer
Your dog has a high prey drive. This is pretty  common. Make sure he has plenty to DO. Occupy his mind and his body. Walk him twice daily , briskly, at heel and for a good walk not just ten minutes. Rain or shine. Put up some toys in your back yard if you have one. tether ball on a pole, hang toys from trees etc. Different sized balls to chase and play with are great. GIve your puppy treat stuffed toys and change them out daily. Lots of versatility. Wear him out at least three times per week. PLay fetch until he is panting and tired., have him run on a tread mill a few times a week. Take him to a dog park, get him involved in obedience. He is a herding dog and he has strong herding instincts. HE has to learn that herding your cat is unacceptable. Use behavior modification. Remember this is an instinct and much harder for your dog to control. Leash him and use a sharp tug not a jerk when he goes after your cat. Say NO in a firm voice. step between them, use a sharp CHH sound and cup your hand, giving him a firm poke NOT hard just an attention getter, with your hand in his collar area.  Your dog's behavior will escalate if you don't contain it. Alsogo to alpha dog boot camp on the web for many great suggestions to help keep your pack in order
Cindi