Hi all, I’m new here! For the past week I’ve noticed my 7 Y/O German Shepherd licking his rear left foot but every time I inspected his pads and inbetween toes, I didn’t notice anything. A few days ago after a little trim of the fur, I noticed there is a dark blister type sore near his pads. It’s around 1 inch away from has bottom pad going up to his heal. Since then I’ve been cleaning twice a day with salt water and applying a tea tree ointment for dogs. I put a sock on so he can’t lick up but a few hours later he’s ripped off the sock and is licking again. The ‘blister’ oozes once he’s been licking but the ointment does seem to be drying it out (only if I can keep an eye on the sock and keep pulling it up). Today I’ve wrapped his foot in a bandage, then the sock and then tape to hold it up - so far so good and the sock remains in place. I will take him to vets but for now I hoped to get a little advice on what this might be? The photos attached are straight after I caught him licking on the first day I found the sore.