We have an english bull x staf and when out on walks he wants to kill all other dogs he meets but when introduced to dogs in the house its all play with no agression.Any one have any ideas why?

thats probably a good sugestion.He is a mummys boy lol

And is he on a lead when he does it ?

__________________

oh definatly yes.I wouldnt dare take chance of him not being on lead now.He used to be ok of lead and was ok with other dogs but he just changed one day so then i started to put muzzel on and let of lead but he still tryed to eat other dogs.So its on lead every time.Makes me sad as he loves to run about but i cant take the chance of him attacking another dog.

its a shame but some dogs are just like that,,,my smudge trys to attack other people while on lead,,,and i can't seem to brake this behaviour as training dosn't seem to do anything so now i just keep him on lead if other people are around,,,

__________________

Keep Dreaming Smudge! HAHAHA

how old is he???
has he been neutuered???

__________________

Keep Dreaming Smudge! HAHAHA

He most likely is scared when a dog is on the lead and meets either new people or dogs they have no option of running away , so they turn to thier next option fight !! in your house he isnt on a lead so when he is introduced to another dog if he feels threatened he has the choice of leaving the situation he is scared by .

__________________

hes 7 yr olds and is neatured.He certainly not scared when on lead as the reaction is the same on or of lead.We used to have a pub and there was no problem with other dogs then even when other dogs went for him.He would just walk away and not go near them.Im inclined to think its a protection issue and that iv made it worse by going into a panic on seeing another dog and he reacts to that now.Iv tried to stay calm and in control but its not easy when i know whats gonna happen.Thinking back there was an incident where he was attacked by a mastif but im not certain this was when his behaviour changed.We love him reguardless and are very carful not to allow him the chance to hurt another dog, its just a shame.