How much tramadol you give your dog depends on the size of your dog. Smaller dogs do not need as much tramadol as larger dogs need to relieve pain. If you give too much tramadol your dog is likely to have more severe side effects. The tramadol dosage for dogs is usually between 0.45 to 1.8 mg per pound of body weight (1mg to 5 mg/kg). The frequency varies depending on what you are giving it for. For general pain, it is given every 8 to 12 hours, but for cancer-related pain, it can be administered every 6 hours.