TL;DR: Swallowing a penny is a serious medical situation for cats because post-1982 pennies contain zinc, which can cause fatal toxicosis and internal blockages. Seek veterinary care within hours to prevent life-threatening complications like anemia or kidney failure.
What happens if my cat swallows a penny?
- When a cat ingests a penny, it is classified as a foreign body ingestion that poses both physical and chemical risks.
- Modern pennies minted in the United States after 1982 are primarily composed of zinc with a thin copper coating.
- When exposed to the acidic environment of a cat's stomach, the zinc can leach into the bloodstream, leading to potentially fatal zinc toxicosis.
Is my cat eating a penny considered a veterinary emergency?
The urgency level for a cat swallowing a penny is Medium. While it may not require the same split-second response as a respiratory arrest, it requires veterinary attention within hours, not days. Risks include:
- Zinc toxicity, which can cause the destruction of red blood cells (hemolysis).
- Secondary conditions such as anemia, kidney failure, and liver damage.
- Life-threatening gastrointestinal obstruction if the coin does not pass or dissolve.
How can providing a photo help my veterinarian triage my cat?
Providing your veterinarian with a photo can be incredibly helpful for triage. Visual aids help the veterinary team assess the severity of the situation through:
- A photo of another penny of the same type next to a ruler to confirm the size and potential material.
- A photo of your cat’s gums to check for signs of anemia or jaundice.
- A photo of any vomitus to help the team prioritize your cat for immediate care upon arrival.
Clinical Context (Merck Veterinary Manual)
Ingestion of USA Lincoln pennies, particularly those minted after 1982 (97.5% zinc by weight, ~2,440 mg of elemental zinc), poses a significant risk of zinc toxicity in cats. The low pH of the stomach causes the release of free zinc, forming soluble, caustic zinc salts that are absorbed in the duodenum and distributed to the liver, kidneys, and other organs. These salts have direct irritant and corrosive effects on tissues, interfere with the metabolism of other ions, and inhibit erythrocyte production. Clinical signs of zinc toxicosis include anorexia, gastrointestinal upset, weakness, regurgitation, polydipsia, and polyuria. Radiographs may reveal metallic densities within the GI tract. Blood zinc levels >2 ppm are diagnostic for zinc toxicosis.
Chapter: Toxicology
Source: The Merck Veterinary Manual, 11th Edition (Page 3088)