If you can, check her incision to see if it looks infected. Hopefully that’s not the case. How much does your dog weigh? You can give her 5mg of buffered aspirin per pound of body weight. It’s safe for dogs but not cats. I would give it in a piece of cheese or another food she likes. It will help with pain and inflammation. I’m sorry that she’s hurting. I edited my post to say that she can have a dose every 12 hours.