Why a swallowed penny is urgent for cats
A single penny can release zinc continuously in your cat's stomach over 48 hours, creating far more exposure than a one-time dose. Cats under 4 kg are especially vulnerable because their small body size means even trace amounts of zinc become concentrated toxins. The metal starts corroding immediately in stomach acid, bypassing any protective coatings.
Watch for early signs like gagging without producing vomit or refusing food—these suggest the coin may be lodged. Later, zinc poisoning causes orange-tinged urine as red blood cells rupture. Never wait for symptoms to appear; the damage builds silently during the first day.
How vets handle coin ingestion
Your clinic will likely take two X-rays: one to confirm the penny's location, another after giving barium to track movement. If it's still in the stomach, they may use an endoscope to retrieve it without surgery. For coins stuck in the intestines, surgery becomes necessary to prevent perforation as the zinc erodes tissues.
Blood tests check for elevated liver enzymes and dropping red blood cell counts. Intravenous fluids help flush zinc from the kidneys, while medications protect the stomach lining. Hospitalization for 2-3 days is common to monitor organ function.
The hidden risk of older pennies
Pennies minted before 1982 contain 95% copper and pose less immediate danger, but any coin from 1983 onward is 97.5% zinc with only a thin copper wash. That coating wears off quickly in digestive acids. A 2023 study found modern pennies release zinc 40% faster in feline stomachs than canine ones due to differences in gastric pH.
Check the coin's date if possible—this changes the urgency. Pre-1982 coins may pass naturally with monitoring, while post-1982 pennies require aggressive intervention. Never induce vomiting; it risks aspirating the coin into lungs.
Long-term effects even after removal
Zinc's damage continues working after the coin is gone. Destroyed red blood cells can take weeks to regenerate, leaving your cat anemic and easily fatigued. The liver may show elevated enzymes for months as it processes released metals. Follow-up blood tests at 7 and 30 days post-exposure are crucial.
Provide high-iron foods like cooked liver (in moderation) during recovery. Watch for lingering weakness or yellowing eyes—these signal ongoing hemolysis. Some cats develop lasting kidney sensitivity requiring prescription diets.
For a dose worked out against your pet's weight, use the Zinc & Coin Toxicity Calculator.