COVID-19 most likely made the leap from an animal species into humans, perhaps via the bat, gaining potency along the way. This is a story familiar to vets and animal owners used to parasites, for example the liver fluke spreading between cattle, sheep and horses by way of water snails.
There is no evidence that the current virus causing Covid-19 directly affects horses. However, it is still primed to have a serious indirect effect on equine health and welfare. You might ask, how?