How does zinc destroy red blood cells?
Zinc is a heavy metal. Once absorbed, high levels damage red blood cells (haemolytic anaemia) and can injure the liver and kidneys. Coins stay in the stomach and keep releasing zinc, so symptoms can build over 1–3 days.
About the dose levels
Single coins rarely cause poisoning in large dogs, but one penny can be toxic to a small dog. Zinc poisoning in dogs is reported above roughly 1–2 g of zinc total. The calculator shows mg per kg.
Single coins rarely cause poisoning in large dogs, but one penny can be toxic to a small dog. Zinc poisoning in dogs is reported above roughly 1–2 g of zinc total. The calculator shows mg per kg.
Signs to watch for
- Vomiting, diarrhoea, not eating (may start days later)
- Pale or yellow gums (anaemia)
- Lethargy, weakness, dark urine
- Rapid heart rate, fast breathing
- Liver/kidney signs in severe cases
What to do right now
- Call your vet if your dog ate any coins or zinc pills — even one penny in a small dog.
- X-rays can show coins; the vet may remove them before they release too much zinc.
- Bring the zinc pill bottle if supplements were eaten.
- Treatment may need a blood transfusion in severe anaemia.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.
For a dose worked out against your pet's weight, use the Zinc & Coin Toxicity Calculator.