Vomiting, diarrhea, blood in stools (they appear black and tarry, as if they contain coffee grounds), change in drinking or urinating, changes in behavior (such as depression), restlessness or appetite loss, yellowing of gums, skin or whites of eyes, changes in skin (redness, scabs or scratching). If your pet experiences any of these symptoms, stop medicating immediately and contact Delton Veterinary Hospital.