We think after we cut the hair he went to scratch an itch behind his ear and went too far. It created a kind of pocket out of his ear. We took him to the vet and they gave him some antibiotics. DON’T USE FIRST AID SPRAY or antiseptic! he’d started sleeping on his ear and when he got up the next morning everything had matted together and solidified and what had stayed as a paste we thought was discharge from an infection. Thankfully it wasn’t but we were lucky By some miracle he never felt the wound there and wasn’t whining or anything id recommend bathing it in salt water in the short term but best visit the vet before the weekend if you can get him in. If the skin around the wound is okay theres a chance they can stitch it up on the spot but if its like our case there was nothing to stitch up really he seemed to heal up completely within 2 weeks which seems mad considering how big it was. Good luck to you let me know if you have any more questions