Question: will one grape hurt a dog?
Answer: Eating Just One Grape Could Damage Your Dog's Kidneys, Vets Warn. Grapes can be toxic to some dogs and must be avoided. ... Symptoms some dogs show after eating grapes or raisins can include vomiting, diarrhea, lethargy, lack of appetite and difficulty urinating, according to a 2002 "Animal Watch" report from the society.