[yorkietalkjilly]

Terriers are a bit prone to fighting, especially same-sex terriers. Usually it is one terrier disciplining the other terrier, which is either anxious or one trying to usurp the alpha dog's place in the hierarchy of the little pack. They also fight over resources of food, toys, or anything a dog considers to be his until one becomes submissive and allows the alpha to take what he wants. If that never happens, keeping them apart during these times or muzzling the biter might be all you can do unless you are quite good at reshaping dog behavior. If you are, then work on your alpha to retrain him not to attack. This can get you bitten in that you have to be there when a fight occurs and approach the biter to put your hand in a claw fashion over the back of his neck and pinch in a bit and say "No!" in a very low, stern, almost growling tone. Then use your body to back him off of the other dog and walk him away and to another area or they will restart the fight. You could start one of the free methods of Nothing In Life Is Free programs on the biter to show him that he isn't truly alpha of the pack- you are and you are the only disciplinarian in the pack. If the problem keeps up, I would probably hire a very experienced dog hierarchy to give you some pointers as to how to help avoid and tamp these things down and encourage your two to become compatible pack members. If both dogs seriously are alpha-natured terriers though and you are not a very strong leader with them, you may never get a satisfactory solution except to separate them when outside or muzzle the one.