The September 2011 issue of ScienceWorld from Scholastic
Check out my latest TV appearance.
I love obscure facts. The best, obscure facts are those which are relatively important, and make people wonder why they remain obscure. Eating a penny can kill a dog. There’s a good. one. 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.
For 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. I, alone, have seen approximately 10 in the past 3 years.
A quick search on Google will convince you that zinc toxicity from US pennies minted after 1982 is not a major problem. 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:
Office of Public Affairs
Tell him that you read about it on davidbessler.com.
When I first found out I was moving down to Florida, I was excited to practice in a whole new world. Tampa is different from New York in so many ways. Then, the excitement was replaced by fear. Perhaps the new world of Tampa will bring new challenges. There are emergencies that are common in Tampa, but virtually non-existent in New York City. I made a list of such emergencies. My list included complications from heart worm disease, bufo (toad) toxicity, sago palm toxicity, and snakebites. I scrambled to learn as much about these emergencies as I could.
Many pets are bitten by snakes every year. Down in Tampa, this is a daily occurrence. Most of the bites are from crotalids, a family of snakes which includes rattlesnakes. Some pets are bitten by coral snakes, members of the elapidae which includes cobras. Coral snake venom is different from rattlesnake venom. Coral snake envenomation causes life-threatening neurologic problems, whereas rattlesnake venom causes other problems such as bleeding disorders, severe inflammation–often facial swelling as seen here–severe infections, and sometimes death.
- Some links about rattlesnakes
- Pictures of rattlesnakes in Florida
- Florida’s Venomous Snakes
Dogs are often bitten on the face when they stupidly try to sniff or bite a rattlesnake. The bite is often very painful. Not all rattlesnake bites contain venom. A small percentage of bites are “dry.” However, waiting to find out whether or not the bite contained enough venom to cause problems, is often a deadly mistake. Treatment includes intensive care hospitalization with close, round-the-clock monitoring for some of the life-threatening complications. Antivenin (sometimes known as anti-venom) should be administered as soon as possible, but is expensive to maintain, and may not be available everywhere. IV fluids are given in the hospital, as well as IV antibiotics and pain medication. Doctors will want to monitor coagulation (blood clotting) times as well as general bloodwork to make sure all the organ systems are continuing to function properly. Despite appropriate therapy, some dogs still die from snakebites.
Believe it or not, the dog in the picture above is a miniature pinscher. His face is dramatically swollen. While this is a funny picture, the danger to the dog is clear. Swelling this severe could easily close off the dogs airway suffocating him. This is the least life-threatening of all the potential complications of snakebite.
Add 1ml/kg of fentanyl (0.05mg/ml) to a 50ml bag of saline.
@ 3-6ml/hr = 3-6mcg/kg/hr
will last 8 – 16 hours
Morphine: 0.5mg/kg IM
Lidocaine: 1 mg/kg IV
Ketamine: 0.25 – 0.50 mg/kg IV
CRI in a bag:
Morphine (15 mg/ml) 8ml/L
Lidocaine (20 mg/ml ) 50ml/L
Ketamine (100 mg/ml ) 1.2ml/L
Morphine 2 ug/kg/min or 0.12 mg/kg/hr
Lidocaine 17 ug/kg/min or 1.0 mg/kg/hr
Ketamine 2 ug/kg/min or 0.12 mg/kg/hr
Can go up to 3ml/kg/hr without exceeding any dose ranges
Cats – until more data is obtained, lidocaine’s use in cats cannot be recommended due to potential toxicity issues. If it is used in cats, do not exceed 10 ug/kg/minute, and monitor carefully for seizure activity and cardiac abnormalities (bradycardia).
CATS – LIDOCAINE (20 mg/ml): 300 mg/500 ml diluent = 15 ml/500 ml diluent = 30 ml/1000 ml diluent
Deliver at 1ml/kg/hr fluid rate = 10 ug/kg/min or 0.6 mg/kg/hr
To substitute fentanyl for morphine at a dose equipotent to the morphine dose above add:
FENTANYL (0.05 mg/ml): 0.6 mg/500 ml = 12 ml/500 ml diluent = 24 ml/1000 ml diluent.
Deliver at 1ml/kg/hr fluid rate = 0.02 ug/kg/min or 0.0012 mg/kg/hr
- Insensible losses (respiratory) = 22 – 33 ml/k/day (0.9 – 1.3 ml/kg/hr)
Sensible losses (Urinary) =26 – 44 ml/kg/day (1 – 1.8 ml/kg/hr)
Total maintenance = 44 – 99 ml/kg/day (1.9 – 3.1 ml/kg/hr)
Average = 2.5ml/kg/hr
- Insensible loss is almost pure water (hypotonic fluid loss)
Sensible loss is an isotonic fluid loss
- Vomiting, diarrhea, osmotic diuresis are all isotonic losses
Diabetes insipidus, panting, water deprivation are hypotonic losses
Addison’s disease is a hypertonic loss
Total body water = 60% of body weight
Intracellular water = 40% of body weight
Extracellular water = 20% of body weight
Interstitial water = 16% of body weight
Plasma water = 4% of body weight
Intravascular volume = 7% of body weight (plasma volume + RBC volume)
Hematocrit = 3% (RBC volume) / 7% (intravascular volume) = 43%
Note that IV volume is part extracellular and part intracellular
Here are some images from last night at The Recovery Room. Spada was on hand for the first time. Kimmel tried on my glasses. All in all we had a pretty good time.
The much-awaited exhibit entitled “When Major Appliances Attack” opened today at the Center for Specialized Artistic Exploration. The exhibit features important works from renowned artist Malerie Vailman. Vailman appeared at the opening this morning surrounded by her entourage of body guards and agents. She arrived accompanied by her trendy beau known to the public only as Revin. Vailman, who stunned the artistic community in October with “Still Life with Dryer” has become one of the nations best-known new artists. Vailman is a founding member of the Paris-based Au-Pliance school. The 30-year-old artist says that this piece, “Reinvigorates the idea that art can be both beautiful and also a burned out dryer.” Most of the other, lesser-known artists on hand were locals struggling to break into the scene. Losh Jachowicz, a new immigrant from Poland, was very active in that country’s Vhirlpulvitz and Maytäg movements. Jachowicz was at the show to discuss his new, controversial piece entitled, “Nude: Refridgerated.” When asked to comment on his body of work, Jachowicz said, “I wish people could learn to see past my body.” … Touché Jachowicz.
Simon’s glasses finally arrived today. We put them on and he actually sees a lot better. He can actually see the cheese and yum-yums we give him. He still has to get used to them. Right now, he’ll leave them on as long as he is distracted but the first chance he gets, he takes them off. My plan is to distract him while he wears them for longer and longer periods of time until he just keeps them on.
- About Doggles
- Doggles are protective eyewear for dogs. They are actually goggles for dogs, hence the name. Unlike ordinary sunglasses for dogs, Doggles actually protect dog’s eyes from foreign objects, wind, and UV light.
For all of you who don’t know why Simon needs glasses, a few months ago Simon had an acute case of glaucoma because the lense in his left eye popped out of place. We treated him in the middle of the night and the next day he needed to have that lens removed. The lens in the other eye was on the verge of luxating too and so we took that one out as well. It took him a long time to recover from the surgeries but is doing much better now. He will still, occasionally bump into things but is getting along pretty well. Marni used the techniques she uses to figure out the glasses prescription for babies and figured out roughly the prescription Simon would need. Marni’s dad (the optician) had the lenses made. The lenses were fit into frames made by Doggles (sunglasses for dogs) – and now, Simon has glasses.
Today, Mip Chunda, the yellow lab saw white-boy rapper gone veterinarian, B-Rodskee in an appointment destined to be called the ear-job of the century. The all-star guest list included otitis media mogul Kue Simmel, and psychic advisor to the stars, Lion Devitan. Porn star Coco Nelson Chajmovic (AKA Bavid “Normal Kidney” Dessler) was on hand as well. Onlookers were amazed as Mip tore off a small peice of B-rod’s left earlobe and spit it into the audience. A young girl, later identified as eastern pop-diva Rothra Motten-yogurt, caught the resected appendage and rushed off to have it encased in lucite. Davidbessler.com reporters caught up with the young idol later to discuss her trophy.
“It’s really more like a dream,” Motten-yogurt said. “I thought I would end up with a sock or perhaps a piece of belt. But to come away with an actual body part is more than I could have ever asked for.”
Admissions to the show were free thanks to the kind and generous donations of the CSVC (Center for Special Veterinarian’s Cats).