I do have buffered dog aspirin here. They are 120 mg tablets and dosage reads like this:
1/2 tablet (60mg) per 10 lbs of body weight every twelve hours. Not to exceed six (6) in a 24 hour period.
Should be given within 30 minutes after the animal has ingested an amount of food equal to 1/3 or more of its normal daily amount.
Should not be given to cats or puppies less than six months old.
If vomiting, diarrhea, depression or loss of appetite occurs, stop administration and consult your veterinarian.