Hi, Welcome to JustAnswer. I am a licensed veterinarian and I'm here to help you. I'm so sorry to hear about your Sashi. Aspirin can be used in cats for analgesia and the dose is 10mg/kg of body weight every 2-3 days (so very infrequently). However, if she is on metacam or other pain reliever at this time, then aspirin would be contraindicated.