Zinc (pennies minted after 1982, some hardware/zippers, zinc oxide creams)

How Much Is Dangerous

A single swallowed zinc-containing coin or piece of hardware, if it remains lodged in the stomach, can cause serious illness over the following days as zinc continues to leach out — the real danger here is cumulative from an object that stays in place, rather than from any single brief moment of exposure. Zinc oxide-based diaper rash creams and sunscreens represent a separate, generally lower-risk exposure category than a swallowed coin specifically, since they don't remain lodged in the stomach the way a coin can, though large ingested amounts of any zinc-containing product still warrant veterinary attention.

Symptoms

• Vomiting and diarrhea
• Lethargy and weakness
• Pale or yellow (jaundiced) gums as red blood cells break down faster than they can be replaced
• Dark or unusually discolored urine
• Loss of appetite
• Abdominal pain

Time to Symptoms

Can begin within 1–3 days as zinc progressively leaches from a retained object, and characteristically worsens the longer the object remains in place without being identified and removed.

First Aid Steps

• Contact a veterinarian promptly if a coin or any zinc-containing object may have been swallowed
• X-rays can confirm whether an object is present and pinpoint its location within the digestive tract

What Not To Do

• Do not assume a swallowed coin will simply "pass on its own" — zinc-containing coins left in the stomach actively cause ongoing, worsening harm the longer they remain, unlike many other swallowed foreign objects that might reasonably be monitored
• Do not delay imaging to confirm or rule out a swallowed coin or zinc object if this is even suspected, given how the situation actively worsens with time rather than staying static

Veterinary Treatment

Removal of the object — endoscopically or surgically, depending on its location and the specific clinical situation — is essential and represents the actual definitive fix, since the anemia will not fully resolve as long as the zinc source remains in place. Supportive care and blood transfusion may be needed for significant anemia in the meantime, but this addresses the consequence rather than the ongoing cause.

Toxic Compound

Zinc, which causes hemolytic anemia — destruction of red blood cells — and can also affect the pancreas and kidneys with significant exposure. Pennies minted after 1982 (in the US specifically) are primarily zinc with only a thin copper coating; the acidic environment inside the stomach gradually corrodes through that thin coating and releases the underlying zinc, meaning a swallowed coin left sitting in the stomach represents a genuine, ongoing source of exposure rather than a single, one-time event that's done once the coin is swallowed.