I realize horses require larger doses than people but it’s hard to imagine overdosing a horse without realizing they were dispensing a whole lot of meds. I wonder what they all needed medicated for.
From what I understand it wasn’t the amount. It was the wrong mixture. Not sure what they were being medicated for. Could have something to do with the different type of feed here in the States. Horses don’t like their diets changed.
It’s a routine supplement — B12, selenium, potassium, and magnesium — all stuff that any 10 year old can buy off the supplement shelf at any drugstore. Math matters. Most substances can kill in large enough quantities, even water. I suspect the selenium in this case, because potassium toxicity is so well-known (plenty of human deaths from potassium overdoses in hospitals) and the amount of potassium it would take to kill a horse would be massive. And potassium would probably have killed faster if it was going to at all — it’s commonly used for deliberate lethal injections.
I bumped into a story about a 75 year old Australian man who read on the internet that selenium might prevent prostate cancer, purchase bulk sodium selenite powder (the form of selenium in the brand-name product that was supposedly copied for these horses), took 100,000 times the safe dose (he took 10 grams), and died 6 hours later despite intensive medical treatment. That sounds like about the same time frame as these horses, who had reportedly been given the supplement earlier the same day.