Along with the aspirin, to reduce stomach upset, I would also give Pepcid A/C (Famotidine). The dose based on your dog's weight is 15mg every 12 hours. You can also purchase this over the counter.
Watch for vomiting, diarrhea, loss of appetite, and lethargy as signs of illness from the medication.I hope this information helps!_____________________________________________________________________Please click "ACCEPT" if the information I have provided has been of help so I receive credit for my work. Bonuses are always welcome and Feedback is appreciated. Thank you.The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would highly advise contacting your regular veterinarian.