Cornelius Betti
Cornelius Betti voted up Gator Blu's answer

I have heard the theory that dogs have a fight or flight instinct and by being on the leash you have eliminated the "flight" option, making them more fear aggressive. How you hold the leash can be making the problem worse. By tugging on a leash or keeping it tight can enforce the feeling of … Read more

Cornelius Betti
Cornelius Betti voted up Gator Blu's answer

I have heard the theory that dogs have a fight or flight instinct and by being on the leash you have eliminated the "flight" option, making them more fear aggressive. How you hold the leash can be making the problem worse. By tugging on a leash or keeping it tight can enforce the feeling of … Read more

Cornelius Betti
Cornelius Betti voted up Anonymous' answer

It could very well be that your dog feels she is protecting you since she is tethered to you, and at the dog park she is on her own to play and socialize. 

You may not have a dog that will be able to be sociable during walks, and that's okay. It a "job" for … Read more