Care of the Virginia Opossum

There has been much said about how opossums are killing horses by spreading this parasite in areas where they graze, but let’s look at the facts: 

 

EPM was first discovered in the 1960s by Dr. Jim Rooney. The disease is considered rare, though recently an increasing number of cases have been reported. Outdated research at the University of Kentucky identified the opossum as the definitive host of the disease. However, since that time it has been learned that all wildlife can be a host and in particular,  the "barn cat.” 

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Yes, possums can carry EPM....but so can a myriad of other animals and birds. Barn cats are one of the most frequent carriers because they kill rodents and other small carriers of this disease. Horse owners would have to literally keep their horses in a protective bubble where no bird can fly over and leave its infected droppings and no mammals can enter to do the same. I sympathize with horse owners, but do not understand why they continue to place blame on just 1 species, in this case, the opossum, or why they will not open their minds to updated research regarding this disease. There are so many outdated websites that give false and biased information on this disease. 

 

EPM has been discovered in horses that live in areas of the country where the opossum does not even exist. There were cases of EPM in the Rocky Mountains of Colorado and Utah... where no opossum has ever lived. 

EPM is caused by the parasite Sarcocystis neurona that affects the central nervous system of horses. The life cycle of S. neurona is well described. In order to complete its life cycle, this parasite needs two hosts, a definitive and an intermediate. In the laboratory, raccoons, cats, armadillos, skunks, and sea otters have been shown to be intermediate hosts. The opossum has been proven not to be the definitive host of the disease. Furthermore, it has been discovered that horses most commonly contract EPM from grazing or watering in areas where wildlife or cats have recently defecated. However, horses cannot pass the disease among themselves, that is, one horse cannot contract the disease from another infected horse. The horse is a dead-end, or aberrant, host of the parasite.

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Try this site for a more accurate over view:

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American Association of  Equine Practitioners:

http://www.aaep.org/info/horse-health?publication=750