This product makes me so angry. The fact that aspirin can legally be marketed for dogs when it has an extremely narrow margin of safety is just unbelievable. Aspirin at a very low dose is safe, but doesn't have a noticeable effect on pain. At a much higher dose, it is great for pain, but extremely unsafe. Dogs do not respond the same way we do to NSAIDs, which is why other human NSAIDs (ibuprofen, etc) are not considered safe for dogs. I have personally seen dogs who died from a perforated stomach after a few doses of "dog" aspirin at the dose prescribed on the label. You could not pay me to give this product to my beloved dog, and honestly if I went to a vet who recommended it I would be finding a new vet. There are numerous newer drugs that are infinitely safer, and any vet who recommends aspirin is not recommending the best for your pet. In addition, this should absolutely NOT be used for post-op pain, because most vets give an NSAID at the time of the surgery and this product actually interacts with it (as well as several other common medications) to cause more severe side effects. PLEASE don't buy this product!