A. Keep it clean with salt water bath twice or three times daily. Try to stop him if he is scratching the wound ( a buster collar could help). Sudocream could help as has a bacteriostatic effect.
If not drying up and scabbing in the next days, he would need to be seen by your vet and potentially have antibiotics ( and maye a stitch up!)
A. You can clean it with lukewarm water, dry it and put an over the counter antiseptic cream. If the wound is behind the ear there is a good chance it is self inflicted.
The most common conditions to cause this would be an ear infection, although it could also be allergies, fleas or mites.
Take him to the vet as soon as you can to get him the right treatment.
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