Possums are also carriers of EPM and infect horses by climbing into their feed buckets and pooping, the the horse injests the poop. My aunt says a good possum is a dead possum.
Parasite
Sarcocystis neurona is the most common cause of equine protozoal myeloencephalitis (EPM) in horses in America. It is a single celled parasite belonging to the group called coccidia (Apicomplexa: Sarcocystidae) with opossums as the definitive hosts and a variety of mammals as aberrant or natural intermediate hosts . Only asexual stages have been identified in the aberrant intermediate hosts, and they are confined to the brain and spinal cord, and any part of the central nervous system (CNS) may be affected. In histologic sections of CNS, individual merozoites are about 3-5 um long and contain a single, centrally located vesicular nucleus. The sarcocysts are microscopic (~700 um long) with a 1-3 um thick sarcocyst wall. The bradyzoites are slender and tiny (~ 5 um long). Sarcocystis neurona sporocysts from opossum faeces are ~ 10 x 8 um in size.
It has the most unusual life cycle for any species of Sarcocystis as unlike other species of Sarcocystis, S. neurona has wide host range for its intermediate hosts. Opossums (Didelphis virginiana, D. albiventris) are its definitive (reservoir) hosts and excrete oocysts and sporocysts (environmentally resistant stage)in their feces. Raccoons, armadillos, sea otters, skunks, cats and possibly other mammals are intermediate hosts. These animals ingest the sporocysts , which after many asexual cycles, lead to the development of sarcocysts (resting stage) in their muscles. Infection of the final host is by the ingestion of the sarcocysts from the muscles of the intermediate hosts. The bradyzoites are released in the intestines of the definitive host. They undergo a sexual cycle and this ultimately result in the production of sporulated oocysts, which are excreted in the feces of the opossum. Horses are considered its aberrant hosts because only schizonts and merozoites (no sarcocysts) have been identified , confined to the brain and spinal cord.
I don't want to debate possums, just wanted to give some info that may not have been known. What you do with your predator problem is completely up to the property owner in my mind.
