Just as dog owners often don’t realize their canine friends are too heavy, they may have a blind spot about another threat. Surprisingly, the lowly penny can become a lethal weapon against dogs—specifically pennies minted after 1982.
Although all pennies are equal in value—one cent, no matter what year it is— their compositions are not. Pennies that were produced between 1962 and 1982 are predominantly copper (95 percent), whereas pennies churned out in 1982 and after are mostly zinc (97.5 percent).
Zinc is an essential mineral but is undesirable in excessive amounts. When pennies meet the acid in a dog’s stomach, the zinc gets released rapidly, which can destroy red blood cells and, in turn, lead to a number of debilitating conditions, including kidney or liver damage.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Certainly no one was thinking about dogs when the U.S. Mint approved the transition from a copper to a zinc penny. But if Abraham Lincoln were alive today, I’m sure he would say, “One score and thirteen years ago, our fathers brought forth on this continent a new penny, conceived in zinc. So, please, keep them out of reach of your dogs.”
Subscribe to Support Independent Journalism
Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.
When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.
Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber
