My boyfriend's 1 year old Shih Tzu puppy had a black/ blue item in his vomit. The item resembels the black sponge of a small sponge hair roller. He's a very energetic/ happy dog, but he becomes slow and somber when this happens, like most dogs after vomiting. Have you ever heard of anything like this? This isn't the first time that this has happened, but I would like to know the cause of it.

