A record hurricane season and drought conditions throughout the United States last year hammered home the message that horse owners need to be prepared for the effects of extreme weather conditions. The immediate effects of these conditions are usually visible in the form of increased feed prices, but there are many other underlying effects that are not always readily recognized by horse owners.

Drought and wet-weather conditions can create environments that are accommodating to molds and fungi in hays and grains, and these conditions can damage grasses, allowing weeds to outcompete them in pastures. This can be especially dangerous when pastures are overgrazed and contain toxic weeds or nutrient accumulator plants.

Molds and Fungi

Ann Swinker, PhD, extension horse specialist at Pennsylvania State University, says molds can be a serious problem when horses are exposed to them, more so than most other types of livestock. She says horse owners are generally wary of molds present in their hay, but they aren’t always able to recognize molds or fungi present in their grain or even in their pasture fields