Pennies made later than 1982 contain zinc, which is toxic for dogs and cats if ingested, according to the AVMA. A Colorado dog died recently from the effects of a single penny that she ingested along with a quarter. Once absorbed, zinc harms red blood cells, leading to symptoms including vomiting, diarrhea, lethargy, lack of appetite, red urine and jaundice. "Zinc toxicosis is more commonly seen in dogs, but cats can get sick from eating pennies, too," said veterinarian Rebecca Jackson. "Be sure to bank your spare change before curious pets can get their paws on it -- and if they do, get them to the emergency vet immediately."