my dogs keep getting sores along their lips/outside of their mouth, what can i give them to get rid of their sores?

Rather than treat this apparent symptom, why not dig in and look to the root cause of the sores instead?

The sores are symptoms of the body out of balance. So I would ask you this - what are you feeding your dogs? If you can address the cause, the symptoms will go away of their own accord. 

My jack russell is having this problem too.  Several days ago i noticed some hair missing from the bottom of her jaw under her lip, this has since gotten bigger (about the size of a half dollar) and has gotten a little swollen.  I started putting triple antibiotic on it and a couple days ago started putting cortisone cream on it as well.  This morning I also noticed a bit of redness on the outside of the corner of her mouth as well, so put some cortisone cream on that too.  By this evening there is a big sore on the corner that has also swelled up, with all of the hair gone now (this one is about as big as a nickel).  I'm guessing it may have gotten worse much quicker there since she can lick it easily, at least more so that the bottom of her chin.  She's almost 7 and has never been allergic to anything.  I'm thinking of giving her a small amount of benadryl (I've found 1mg/lb is ok).

Any idea what may be causing this?