I hope the vet can figure out what is wrong with your dog
I wonder if the dog is scared of storms and scratch so much that it makes sores
I take an unscented fabric sheet and rub on the back of my dogs neck before the storm gets to our house and sure has calmed her down and she is now no longer scared of storms and it worked
my friend in Texas also did this to her 3 dogs (2 are labs and a medium dog) and they are no longer scrared of storms
Good Luck and let us know what the vet says.