Aggressive Golden Retriever

Question
When I take my 4 year old female golden retriever for a walk she always acts aggressive towards other dogs while on the leash. But if shes off the leash she is really friendly. Is this a protection issue or something?

Answer
That is a common problem, but I am not sure exactly why.  It could be protective or a feeling of being at a disadvantage on leash.  The best thing may be strong leadership on your part.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat.