Let's not let our natural concern for the well-being of our furry friends give us the wrong impression about these two substances.Methanol is actually about 3 times MORE toxic than ethylene glycol. (Although neither one is "especially toxic" in the taxonomy of such things.) The fatal dose of ethylene glycol for an adult human is about 100 ml (half the contents of a coffee mug). Pure methanol has a fatal dose of more like 30 ml. Also, unlike glycol, methanol can be absorbed through the skin, or breathed as vapors, and there have been cases of human poisoning both ways. Methanol is flammable. All-in-all, methanol is much more dangerous to be handling than ethylene glycol. Ethylene glycol is hazardous to animals not because of its extreme toxicity but because of its sweet taste. You will recognize the taste and smell if you've ever tried to diagnose that leaky radiator or heater core by blowing into the hose. Methanol, on the other hand, smells and tastes about as appetizing as gasoline. If you park your tractor on a dirt or gravel surface, and the tire springs a leak, it is unlikely that enough fluid can accumulate to poison Fido, even if he laps industriously at the valve stem. But a substantial puddle on a concrete floor would be enough to be a problem -- which is where the whole issue came from. You can learn more about the two substances at the attached link. I found several things surprising about the two: 1) Normally, the body breaks down poisons into less toxic compounds. However, for both of methonal and glycol the metabolites are much more toxic than the original substance. 2) As a result of 1), the initial symptoms of poisoning are a relatively benign intoxication. It takes a while (6 to 12 hours) for the metabolic byproducts to accumulate and severly damage the body. 3) The primary "antidote" for both is intravenous ethanol. That's right, good old Kentucky Sour Mash #5. It turns out that the liver is much more interested in metabolizing ethanol than methanol or ethylene glycol. By keeping the victim "drunk" for a considerable period, the liver is kept busy "working off the binge" and is prevented from creating toxic metabolites of glycol or methanol. The unchanged parent substance is slowly excreted by the lungs and kidneys.
| 
