For many years (decades) there was a daily newspaper cartoon about Pogo, an opossum, (sometimes just called possum) that lived in the Okefenokee Swamp. He hung out a lot with an alligator named Albert and an owl whose name I forget. Pogo the opossum was cute and clever. One of his famous quotes was “We have met the enemy, and he is us.” I don’t know about clever, but in real life opossums aren’t cute. They don’t look anything like Pogo. . The fact is, they are probably one of the ugliest animals you’ll ever meet.
The first one I saw was a road kill, just two miles from my house about 6 years ago. A few months later I met one in our barn. I walked in to do night check, and there he was, as big as a cat, and a bit scary. Any other wild animal would have scurried away. Opossums tend to stand their ground. This one opened his mouth and hissed at me. Their open mouths are quite impressive, holding 50 teeth, more than any other animal in North America. I’m sure that he was visiting my barn to take help clean up the food that our barn cats had left.
Opossums have quite an appetite. They are true omnivores, eating anything and everything. Insects, small rodents, anyone’s left overs, and all varieties of road kill. They often become road kill themselves while eating out. They have very coarse, scraggly hair. Someone said “every day is a bad hair day for an opossum.” It doesn’t insulate well, and helps to explain their appetite. They have to eat plenty to keep warm.
The opossum tail is long and hairless. They are excellent climbers, and nest in hollow trees and burrows in the woods. The myth that they hang from their tails is not true. What is true is that they really do “play possum” when badly threatened. Their nervous system goes into “play dead mode”, flops them over and for the entire world they look gone, to the point that their eyes glaze over. I understand that you can’t even pick up a heartbeat (and I’m not going to try.) Predators lose interest.
They are North America’s only marsupial. The very tiny young are born after just 12 days of pregnancy, and their first journey is to Mom’s pouch where they spend a couple of months nursing and then work their way up to her back where they are carried for another month or two.
Why do we care about this strange creature? They carry a one cell parasite called Sarcocystis neurona. They pick this up from eating dead birds, skunks, raccoons, and even cats. The parasite is found in the muscles of these animals. It ends up in the opossum’s intestines. Apparently this doesn’t bother the opossum, but when the parasite matures an immature form passes out with the fecal material. This is then picked up by small animals and birds and the cycle continues.
If a grazing horse picks up the parasite it goes to the brain and or spinal cord and not the muscles. It is the cause of the disease EPM (Equine Protozoal Encephalomyelitis). This is a debilitating neurologic disease that can cause a variety of symptoms depending on where it ends up in the nervous tissue.
EPM is still rare in Maine. Opossums used to be rare as well. Will the influx of opposums mean a higher incidence of EPM? Perhaps. Here is what you can do to help discourage them. Keep your horse feed in tightly covered bins. Put out cat and dog food in amounts that will be cleaned up and not left around, especially at night when Pogo comes around looking for snacks.
– David A. Jefferson, D.V.M