- Some coins release zinc
- Hours to days
- Affects: Red blood cells / blockage
Why this verdict for cats
Swallowed coins can cause zinc poisoning and intestinal blockage in cats. Treat any swallowed coin as an emergency.
Warning signs to watch for
- Vomiting
- Pale gums
- Lethargy
⚠ If your cat ate coins
Act immediately — don't wait for symptoms.
- Call your vet or a pet poison helpline right away.
- Note how much was eaten and when.
- Do not induce vomiting unless a professional tells you to.
A swallowed coin sounds like a simple blockage problem, and for most currencies it is. In the United States it is something more serious, because of a change made to the penny in 1982 that almost no pet owner knows about.
How much is safe?
A single post-1982 US penny is a genuine poisoning. Those pennies are 97.5% zinc under a thin copper skin, and stomach acid strips that skin away and dissolves the zinc into the bloodstream. One penny sitting in a dog's stomach can release enough zinc to destroy red blood cells. Pre-1982 pennies are mostly copper and far less dangerous, and most other coins are primarily a mechanical obstruction risk. Zinc also turns up in nuts, bolts, board-game pieces and zippers.
What happens if a cat eats too much?
Zinc poisoning does not look like a blockage. It causes the body to destroy its own red blood cells, so expect vomiting, appetite loss and lethargy first, then pale or yellow-tinged gums, weakness, fast breathing, and urine that looks orange, red or brown. Kidney and liver damage can follow. A larger coin may also lodge and cause the vomiting-and-straining picture of an obstruction on top of the toxicity.
⚠ What to do if your cat ate coins
Call your vet and go in (ASPCA 888-426-4435 · Pet Poison Helpline 855-764-7661), and say specifically that a coin may be involved so zinc is on the table. An X-ray finds it easily, and the treatment is to remove it — usually by endoscopy — because the poisoning continues for as long as the coin sits in acid. Do not wait to see whether it passes. Waiting is exactly what turns this into a transfusion case.
⚠️ Worried your pet got into this?
Frequently asked questions
How do I know if it was a zinc penny?
US pennies dated 1983 or later are zinc. If you cannot know which coin was swallowed, assume the worst and have it removed.
My dog swallowed a quarter — same problem?
Quarters and dimes are copper-nickel, so the zinc risk is low, but a coin of that size can still obstruct a small dog. Get it checked.
More household items for cats
By the CanMyPet Editorial Team · Reviewed against ASPCA Animal Poison Control, the American Kennel Club (AKC) and Pet Poison Helpline · Last updated July 31, 2026.
Sources
- ASPCA — People Foods to Avoid Feeding Your Pets
- American Kennel Club — Dog Nutrition
- Pet Poison Helpline — Poison List