Dog wounds and dog bruises happen. It's a part of a dog's life.
For pain relief, be very careful what pills you give your dog. Only aspirin is safe, and only in low doses. Check with a vet if you're uncertain.
Ibuprofen and acetaminophen (Tylenol) cause damage and severe problems for dogs.
Safely treat your dog's wounds using natural healing aids. These are safe to use, tend not to conflict with other medication, and are over-the-counter purchases. And, it's more help than a dogs licking wounds on their own.