My dog ate a penny, should I be worried?

Simply put, yes. Pennies produced after 1983 contain zinc which is toxic to dogs and cats. Zinc causes hemolytic anemia (destruction of red blood cells) through an unknown mechanism and can also cause vomiting. If you think that your pet has ingested a penny she should see a veterinarian to have a radiograph taken to confirm the presence of metallic foreign material in the stomach. If present, the penny needs to be removed either endoscopically or surgically. Your pet then needs to be monitored for anemia and given blood transfusions if necessary.