How to Cure a Horse, or, the Experience of Knowledge and the Knowledge of Experience

This essay is about horse medicine, or at least about the ways that horse medicine can help illuminate an interpretive problem within the field of the history of science. Chances are that you've heard quite a lot about one particular horse medicine lately, thanks to the popularity of the horse deworming drug Ivermectin as a (supposed) treatment for Covid-19. Despite multiple and increasingly dire warnings from medical authorities, the late summer of 2021 saw hordes of anti-vaccination activists swearing by Ivermectin as a far more effective treatment for the disease than the multiple FDA-approved vaccines available for free across the United States. Facebook groups such as "Ivermectin & how it worked for me" are overflowing with testimonies like one from a user on August 24, 2021, recording his experience taking Ivermectin after a positive Covid-19 diagnosis. This gentleman, who will remain anonymous in this essay, exercised his faculties of observation, dutifully recording his symptoms as they worsened over the course of ten days until he ended up in a hospital emergency room, where he was given an infusion of monoclonal antibodies. Did this experience affect his perspective on Ivermectin's efficacy? Hardly. He wrote on the day after his trip to the hospital that the problem wasn't Ivermectin, it was low dosage: "I needed 50 mg I was only taking 21. So I immediately took 50 mg. [...] I finally slept with my O2 levels staying up!!"(1)