hi,my dog doesnt limp,but every time he runs he turns to his left leg as if something troubling him,any ideas,thanks

He might just have an itch! My dog does that when he has an itch! :)

hi,may i ask what caused that itch,is it a stron itch,because ,my dog really puts attention to his left leg,thanks

Hi
If you dog has been irritated by his left leg for more than a very short time, I think you should have it checked. First try to examine his paw, to discover any cuts or splinters. Then try to gently hold his leg, and put a litttle pressure on a small area at a time. If nothing obvious is detected, have him checked by your vet. In the meantime don't let him run about, in case it makes things worse.
Karen

If he is long coated check there isn't a matt under his armpit (so to speak) that is pulling when he runs.