If your dogs dragging and scooting his butt then he has a blocked anal gland and you need to get him into the vet before it ruptures. If the anal gland ruptures besides nasty and extremely painful it will need to be surgically decried, removed and closed. It does not heal by itself, it will not go away. If left to try and heal on it’s own after it ruptures it can either get infected (usually an ecologist infection since so close to poop) or the thing can sink and cave in, get maggot filled while waiting for it to heal naturally. The dog will die if left alone.
If the anal gland gets expressed then it should settle down and heal, you might have to go back to the vets and have 5hem expressed once or twice after that until it’s totally healed then yearly or biyearly after that for prevention. If your dog goes to the groomer once it’s heaked they can express them while giving the dog a bath.
Please don’t ignore it as it is quite painful. Your dog will want to lick and lick to heal it and besides the pressure he can chew it open to try and relieve the pain and pressure.
I’ve seen several dogs with this condition, butt scooting happens with them all,it’s not just constipation, they are trying to relieve the pain themselves.