Aspirin-free Retrieve Health Aches & Pains for dogs contains White Willow Bark, a natural herb used for inflammation and pain control. White Willow Bark is used in treating mild fevers, colds, infections, arthritis, and other forms of pain caused by inflammation. If your dog has been injured, recovering from surgery, or simply has aches pains, and fevers,then this is the perfect choice for restoring your dogs quality of life. Retrieve Health Aches & Pains is as effective as aspirin, however, White Willow does not cause stomach upset or liver damage as aspirin can. White Willow will not thin your dog's blood unlike aspirin which can cause excessive internal and external bleeding.