Archive for August 3rd, 2006

Aug 03 2006

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Daily Notes 08-03-2006

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I’ve been trying to find information on dogs who circle or twirl on the net. Not much to find, but what I have found recommends low carb, high protein, high in triptophan diets. My reason for needing this information? The Chihuahua I got last year from fellow CCCC members Jack and Joyce Edney exhibits this behavior. He also seems to have some periods of what I can only refer to as “rage” since he gets this hard, angry look in his eyes and bites anything within reach. I’ve been calling them epileptic episodes, but they aren’t exactly like a seizure although he does appear to be exhausted and somewhat disoriented after one. Fortunately, he doesn’t have many of them and I have identified some triggers of them — baths, unfortunately seem to be a trigger as are large, white dogs :(. I thought the recommended diet was interesting and hope to get that confirmed by my vet later today.

In my search, I did find something interesting about zinc poisoining in dogs which I’ve written about in the health section. Since we recently went through this with the Cockatoo, it was alarming to read that dogs are also succeptible to zinc poisoning and from such an unlikely source! No wonder I hate pennies!

Hope all of you are staying cool! Thank goodness they’re saying cooler temps are in order for tomorrow!

Got to run….

Love to all,

 

Margaret

 

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Aug 03 2006

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Pennies are Poisonous!

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Eating a penny can kill a dog. Yes, just one penny. You see the average US Penny minted after the latter half of 1982, has a mass of 2.5 grams. 97.5% of that mass is zinc. That equals about 2.4g (2,400mg). The LD50 for zinc, or dose at which 50% of animals that have ingested zinc will die is 100mg per kg of body weight. That means, that half of the 24kg (53lb) dogs who eat one penny, will die—if not treated. This is a little smaller than an average Golden Retriever. I know you are wondering what the year a penny was minted has to do with anything. You are also probably wondering exactly how a penny might be deadly. You also may want to know if a penny can kill your baby.

221338346.jpgFor the exact mecahnism by which pennies kill, unfortunately, you may need to look elsewhere. Nobody knows for sure how zinc does what it does to dogs. We do know, however, that it causes the destruction of red blood cells in the dog leading to a low red blood cell count. This condition, which may be caused by other factors such as autoimmune diseases, certain drugs, and other toxins, is known as hemolytic anemia. Hemolytic anemia in dogs is ugly. Victims typically present to their vets very lethargic and jaundiced (Note the color of the gums and eyeball in the image). It can be quite frightening. The part we don’t understand yet, is how zinc brings about this destruction. There are theories, but nobody really knows for sure. The fact that zinc causes this destruction, however, is very well established, and unfortunately, veterinarians see thousands of these cases every year.

While a quick search on Google will convince you that zinc toxicity from US pennies minted after 1982 is not a major problem, it’s still something pet owners should be aware of. The majority of sites listed discuss the danger to dogs.

Why pennies minted after 1982? The answer is a bit of a history lesson. It turns out, the composition of the US penny has changed over time. Here’s the rundown from the US Mint:

  • The composition was pure copper from 1793 to 1837.
  • From 1837 to 1857, the cent was made of bronze (95 percent copper, and five percent tin and zinc).
  • From 1857, the cent was 88 percent copper and 12 percent nickel, giving the coin a whitish appearance.
  • The cent was again bronze (95 percent copper, and five percent tin and zinc) from 1864 to 1962. (Note: In 1943, the coin’s composition was changed to zinc-coated steel. This change was only for the year 1943 and was due to the critical use of copper for the war effort. However, a limited number of copper pennies were minted that year. You can read more about the rare, collectible 1943 copper penny in “What’s So Special about the 1943 Copper Penny.”)
  • In 1962, the cent’s tin content, which was quite small, was removed. That made the metal composition of the cent 95 percent copper and 5 percent zinc.
  • The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc). Cents of both compositions appeared in that year.

So, zinc toxicity is becoming more common, as a greater proportion of the pennies in circulation are toxic. Should we call the US Mint and ask them to change the composition of the penny to one less toxic to dogs? I think we should. Please call:

Michael White
Office of Public Affairs
(202) 354-7222

Tell him that you read about it on kemar-k9s.com

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