Vet Tech Corner: U.S. & Canadian Coin Ingestion Treatments
Being the indiscriminate eaters they are, is it any surprise that dogs will swallow coins?
At the ASPCA National Animal Poison Control Center, calls are fielded from all over the United States and Canada regarding foreign-object ingestions, including coins. Here are some facts for you to deposit in your knowledge bank.
Copper, Nickel, Zinc
U.S. quarters, dimes and nickels are made of copper and nickel. Canadian quarters, dimes and nickels minted after 1945 are not made with zinc. The Canadian Loonie coins ($1) and Toonie coins ($2) are also zinc free.
Canadian coins are made of varying combinations of steel, nickel, copper, silver, bronze and aluminum. Ingestions of these coins will cause mild GI upset, mechanical irritation and potentially FBO but heavy metal toxicity is not expected.
However, U.S. pennies minted from 1982 to the present and Canadian pennies minted from 1997 to 1999 are 97% to 99% zinc. Although the toxic dose has yet to be established, ingestion of even a single penny poses a risk for zinc poisoning.
The stomach’s acidic environment erodes through the copper plating and then begins to dissolve the zinc core, so zinc is readily absorbed systemically. Clinical signs of zinc toxicosis include vomiting, anorexia, lethargy, depression, diarrhea and abdominal pain. Hemolytic anemia, acute renal failure and liver damage can occur. Pancreatitis may be present as well.
What to Do
So what is the recommended course of action when an owner calls your office to report that her dog swallowed some coins? If the dog is healthy and stable and the ingestion was recent, emesis could be attempted.
Pennies like to stick to the stomach wall, so if the dog can vomit right away, sometimes the coin can be recovered. Abdominal radiographs may be helpful to confirm ingestion and to quantify number of coins, but may not be able to determine which type of coin was ingested. Emesis could then be attempted.
However, if the coin cannot be recovered, bulk the diet and take daily radiographs. If the coin is still in the stomach 24-48 hours after ingestion, it needs to come out.