What type of collar are using to cause abscess, I have never heard of that happening?
He must have it on too tight and the prongs are wearing holes in the dog's neck: seen it before when people didn't know what they were doing with shock collars They only need to be tight enough to make contact with the skin. Or, the dog was barking continuously despite the collar (those collars make some dogs bark incessantly: shock, bark, shock, bark: there was a stupid woman on here a few years ago who reckoned she'd had a dog screaming continuously for an hour with a shock collar on it :censored