Equine protozoal myeloencephalitis (EPM)
What is EPM?EPM is a disease that affects the brain and spinal cord. It is often caused by the parasite, Sarcocystis neurona, commonly found in the opossum. Research in other states suggests that about 10 to 33 percent of opossums are infected with the parasite in Michigan and Missouri. Horses...
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Newly updated edition of Purdue Forage Field Guide provides essential information on forage management
The fourth edition of the Forage Field Guide from Purdue University Extension is now available for purchase on the Extension Education Store website. Created for livestock producers and the agricultural industries that serve them, the pocket guide is a valuable resource on navigating forage...
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Iv’e known Keith Johnson
(https://ag.purdue.edu/directory/johnsonk)
for over 20 years, he was instrumental in my startup early years as a forage producer. I currently contract to produce horse hay for two summer camps for children one from a church and one through Area 4, both are happy return customers.
There is no better livestock forage expert this side of the Mississippi River. He is one of the world’s leading forage experts. I think I’ll stick with his assessments.
Not arguing, it just my opinion. It appears that possum poo not raccoon poo is the primary transmitter of EPM.
Can EPM be transmitted directly from horse to horse, or is it always through the opossum?
According to the provided information, EPM is caused by the protozoan parasites Sarcocystis neurona and Neospora hughesi, which are found in the opossum. Horses become infected by ingesting food or water contaminated with opossum feces. In <1% of cases, the sporocysts ingested by a horse migrate from the intestinal tract into the bloodstream and cross the blood/brain barrier, causing disease by attacking the horse’s central nervous system.S. neurona cannot be transmitted from one horse to another. A few cases of EPM are associated with N. hughesi, another protozoal parasite.
Therefore, based on the provided information, it can be concluded that EPM is not transmitted directly from horse to horse, but rather through the opossum, which is the definitive host of S. neurona.
- The definitive host for S. neurona is the opossum, and horses become infected when they ingest feed or water contaminated with opossum feces.
- An estimated 50-90% of horses in the U.S. have been exposed to the organism, but only a small percentage (typically <1%) develop EPM.
- Opossums: According to the search results, opossums are considered to be the primary carriers of EPM. They are intermediate hosts for the Sarcocystis neurona protozoa, which causes EPM in horses.
- Raccoons: Raccoons are also mentioned as carriers of EPM, although they are less likely to be exposed to the organism and act as intermediate hosts compared to opossums.
- Skunks: Skunks are mentioned as carriers of EPM, but it is not clear if they are primary or secondary carriers.
- Opossums: According to the search results, opossums are considered to be the primary carriers of EPM. They are intermediate hosts for the Sarcocystis neurona protozoa, which causes EPM in horses.
- Raccoons: Raccoons are also mentioned as carriers of EPM, although they are less likely to be exposed to the organism and act as intermediate hosts compared to opossums.
- Skunks: Skunks are mentioned as carriers of EPM, but it is not clear if they are primary or secondary carriers.