Chester my 3yr 9mth old Staffy has always been fine in the back garden. With 6ft fence all round, he does bark when he hears things, but will come straight in when called...until last week! Our neighbours have got a new dog, we found out when it was in their garden. Chester went to the fence, snarling like a mad dog, wouldn't listen to us. The other dog was barking back, but didn't sound as bad. Eventually got them both inside. but it happens everytime. I'm sure this is a territory issue, but what can I do to stop it, any ideas would be appreciated.