You can give your dog up to 2 aspirin twice daily---that is the maximum dose for a dog your size. If a lesser dose will work then use that. Be sure to give with plenty of food in his tummy.
It is the best for joint pain. Do not give Tylenol or ibuprofin!!
You can go to your veterinarian and get prescription meds too.
My husband is a retired veterinarian--I asked what the dose would be.
Hope it helps.
Chris