Denosyl is recommended, for liver function in dogs and cats. Denosyl SD4 has been shown to increase hepatic glutathione levels in cats and dogs. Forty-five percent of dogs and cats with liver problems have a low hepatic glutathione level. Glutathione is a potent antioxidant that protects hepatic cells. Denosyl DS4 is used to improve hepatic glutathione levels to help maintain and protect liver function. Choose the Denosyl DS4 that's right for your pet:.