Tuesday, October 23, 2007

Toxicology Tuesday, October 23

I broke open my piggy bank for this week's post. But, if I leave them on the floor where the dogs can swallow them, are these pennies


Answer: Toxic

Pennies minted after 1982 are made of 99.2% zinc with only a thin copper coating. Once in the stomach, the stomach acids begin to dissolve the zinc, and it is absorbed and transported to various organs.

Initial signs are associated with the local irritant effect of zinc oxide on the stomach lining. Anorexia, vomiting, diarrhea and a general depression are seen consistently even with short-term exposure or low levels of ingestion. Long-term exposure or higher levels lead to systemic signs. Kidney failure has been reported, but the most common syndrome is Acute Hemolytic Anemia.

Zinc causes damage to the cell membrane of the red blood cells, and the immune system begins to remove these damaged cells. Hemolysis, the break-down of red blood cells, leads to icterus (jaundice, a yellow coloration of the skin and eyes) and anemia, a decrease in the number of red blood cells in the bloodstream.

Treatment involves removal of the penny (pennies), either through surgery or the use of an endoscope, IV fluids and other supportive therapy, blood transfusions in cases of severe anemia, and sometimes chelation therapy, using calcium EDTA to speed removal of the zinc from the system.

Other sources of zinc are the locking nuts on older pet carriers (newer ones are plastic) and other types of zinc-coated hardware, zinc pieces from board games, ointments like Desitin and zinc oxide sun blocks, batteries, some paints and medicated shampoos.


Anonymous said...

Toxic, since pennies are mostly zinc. It causes some sort of blood disorder. If the dog swallows pennies, treatment is to get the pennies out (with surgery if necessary) since the stomach acids erode the pennies and release more zinc.

There is less harm if the penny was minted before 1982, but how are you possibly going to know?

Lisa said...

Ew, toxic, toxic, toxic.

I assume more toxic the more they eat, but what if it's only one penny? (This is NOT a real "Murphy ate..." question.)

Anonymous said...

Last year we were forever finding a penny in our dog's mouth. She's the kind of dog that picks up everything, then comes to you to take it out of her mouth. We couldn't imagine where she was getting them. One day I caught her in the act...she was licking the pennies out of a large penny jar (an old pickle crock). She couldn't put her head in, but the jar was full, so she was licking them and getting them on her tongue.

Thank goodness we saw her. And thank goodness it seems she never swallowed any. She just carried them around in her mouth. Needless to say, the penny jar got covered immediately. Our main concern was choking. We should have been concerned about toxicity but we had no idea there were toxic.

Sara said...

Thanks, I was thinking choking and obstruction but not toxic. Now I know.

nina said...

I would think the metallic odor would keep dogs away. I'm really surprised so many have histories of eating them! I've known of dogs picking up rocks and getting broken teeth, obstructions,...but never coins. I'm glad to know this is a hazard to watch out for. Who knew!

KGMom said...

I thought pennies were copper--mostly zinc? Huh.
I don't know if they are toxic or not--and we have never had a dog go after pennies.
The only thing I do recall reading about copper pennies is the camel caravan drivers would use copper coins as "birth control" for camels, inserting them into their uteruses (uteri?) to keep the female camels from getting pregnant on long trips.

Mary said...

Years ago, my Boston Terrier swallowed a penny (unbeknownst to us) and I found it shining brightly while doing poop patrol in the yard. In one end, out the other. She's eaten a variety of items that would cause concern and is still kicking 11 years later. A penny is probably toxic.

KatDoc said...

I couldn't find a source that indicated x number of pennies per pound of dog as the toxic "dose." I think it depends a lot on how long the pennies are in the stomach, as well as how many there are.

You would think a dog would be smart enough not to eat pennies, wouldn't you, but it never fails to amaze me as to the weird stuff a dog will swallow. Sometimes the dog has help - little kids like to feed coins to the living "piggy bank," but often it is the dog's idea. I wonder if the residual salts and oils from our hands don't make coin-eating seem like a good idea at the time.

Yes, the old "copper 7" IUD used that same principle for preventing pregnancy in women. (Anybody notice I used the correct form of "principle?")

You and your BT were lucky that the penny passed out successfully. As well as the many weird things that dogs eat, I am also stunned by what all they PASS!

Well done, guys! You are all Junior Toxicologists.


Kathy said...

Several days late and several pennies short, but better late than never? My keyboard was dead, so I didn't get to respond on toxicology day. I did know that newer pennies were zinc, and that zinc is toxic, but not how it affected dogs and cats. Zinc is also bad for pet birds, so one has to be careful about what kind of toys they give their birds.