Thank you for your question. Poor guy.
You can try placing an ice cube in a dish towel or washcloth and gently applying pressure.
If you have a nasal decongestant spray, placing a small amount of that on the cotton ball and applying pressure to the wound may cause blood vessel contraction and decrease bleeding.
Pet stores carry a styptic powder that may help.
If your dog has an underlying coag disease, he may have difficulty clotting.
Please let me know if you need more assistance.