Determining a dosage of tramadol for dogs is an exercise in futility. As with people, if the dog has a history of seizures it is important to let your vet know this, and they will likely tell you about alternatives.
While the dosage amounts vary from dog to dog, the tramadol dosage for dogs can be put into effect by using the dog’s weight as the determinant. The usual range is .5 - 1.8mg per pound. This amount, whatever it may be for your pet, will fluctuate with the dog’s weight, but you should always consult and defer the decision to a veterinarian regarding this medication. Once there is a prescription for the amount and duration, it is important to follow the directions and provide feedback on the progress and nuances. Do not attempt to adjust the medication without professional help, as a tramadol overdose can be deadly.
So, on a subject like this, you really need to call the vet. You wouldn't want to make a mistake. Is this prescribed for him? The general dosing guideline is 1 to 5 mg per kg of weight. Hope your dog is better by now. How old is he/she?