Pharmacy made mistake in horse drug
What an awful thing.
I used to work at a company that (among other things) tested animal feeds for active ingredients. Our customers were the major drug companies that also make people drugs. They sold the drugs to feed mills, which blended them into feeds and premixes, and then sent samples to us to verify that they were at the appropriate concentrations. The drug companies paid for this testing so that people didn't accidentally poison their animals and because the FDA watched this with an eagle eye - most of those animals were in the human food chain. Sometimes we got samples marked ADR or ADE, Adverse Drug Reaction or Event. It could mean that animals weren't responding to treatment, so it was suspected that the concentration was too low or the drug wasn't present at all. Or it could mean that animals had sickened or died. There are drugs that are safe for cows and deadly for horses so sometimes we had horse feed that we had to test for those and we always hoped not to find them.
My boss there was one of the most compulsively painstaking people I have ever known. There was a drug in cattle feed we tested for, and the amount could range from 50 to 150 grams/ton. If we reported 83.2 g/ton due to a rounding error when the actual result was 83.3 she got all uptight about it. I always did the nonconformance/corrective action things but I also would tell her: "No animals have died from this." After a while she thanked me for the perspective. In fact, it almost got to be kind of a joke. If one of my techs made a little error like that and I caught it I would take it back for them to fix and sternly say "Cows could die!"
Now horses have died, apparently because someone made a non-trivial error and it wasn't caught. I don't know what kind of legal repercussions there will be, but I know they regret that mistake mightily. Hate when that happens.