I have a 3.5 year old male border collie named Eddie. We rescued him when he was 3 months old. He is a great dog - needed a lot of training (both obedience and fun training such as agility) and a firm hand but he is now a great companion. He started chasing shadows when he was around 1.5 year old. It started with the shadows of flies and butterflies. Of course, we thought it was hillarious and didn't correct him. However, within a few months he had graduated to human shadows. For the last year or so, it has gotten go bad that he lunges at shadows and bites the ground. Thankfully he only does this outside. However, it has become a real challenge to take him to run at a park or play at the beach. As soon as someone else is there, he'll go after their shadows. He has learned to leave my shadow and my boyfriend's shadow alone and goes after strangers. When we try to correct him, he walks away and then 10 secs later, comes back to it. Nothing has worked so far. Even putting him on his side for 15 mins to cool him down didn't work. After a few minutes, he went right back to it. Please, please, please someone help me! I want to continue enjoying the outdoor with my dog!