I have a 10 year old patterdale terrier,indoors or in the garden he is so well trained he will come to the click of my finger he will sit lay down wait speak etc,anything i ask him he would do it and hes entire focus is me. This however changed the split second i put my trainers on and get his lead,all of a sudden im something to jump up at,whine and go insane.I can see the anxiety in him,i put the lead on and hes pulling straight away on the lead,he will pull me the entire 7 miles i walk him.He pays no attention to me,all he cares about is other dogs people rabbits and generally anything he thinks is either prey,or something to playfight with. He Has a strange temperment,sometimes he will attack a dog,sometimes he wont,the size of the dog doesnt matter,hes a hunting dog by breed and comes from working lines,i bush rabbits with him but he had no experience of hunting untill he was about 8 as i used to live in the city.He has always done this since he was a puppy,ive tried choke chains nose collars stopping and waiting for his attention,180 degree turns when he pulls,he has no interest in food (I even took raw meat with me and he just sniffed it and kept pulling!) When i let him off in a field etc,hes recall is fairly good,albeit he wont always come back the instant i call him,he will begin to come back within 5 seconds,but if he sees another dog theres no chance. I have a Jack russell shes the same age but female, she is the most passive dog you could ever see,she will walk along my side with a parade of dogs infront of her and she wont even bother with them,she has no aggression towards other dogs and is good at everything i ask of her in any situation. Whats causing my other dog to do this? im guessing its some sort of pack leadership thing, but then why does he only do it outside the house?