Equine Protozoal Myeloencepalitis :: essays papers

Equine phylum Protozoal MyeloencepalitisEquine Protozoal Myeloencepalitis is a serious neurological malady in horses caused by a parasite phylum Protozoa impression to be sarcosystis neurona. The disease was first identified in the 1960s when lesions and ignition system were seen in the brain and spinal anesthesia cords of horses that had died of severe neurologic disease. Protozoa were discovered on the lesions in 1974, however the vector was unknown and the disease considered rare. Recently the opossum has been isolated as the probable vector and the possible parasite organism identified as Sarcosystis falcatula. (Fenger, 1996)The Sarcosystis protozoan parasites have a complicated aliveness cycle. They exist in two distinct forms. maven in the definitive host (a carnivore like the opossum) and one in a secondary or intermediate host (wild birds that the opossum feeds on). It reproduces in the digestive tract of the definitive host and passes infective sporocysts in the feces , which are and so taken in by the secondary host. There the sporocysts migrate to the muscles and mickle persist for years until the secondary host is eaten by the definitive host. The protozoa are usually very host particularised (requiring a specific carnivore to reproduce), and most likely neither host come on any clinical signs of disease. (U. molybdenum 1999)The horse is an unfortunate casualty in this cycle it is give when feces of the opossum are ingested with their food material. The horse is a inactive host, meaning it is not required in the parasites life cycle and therefore the disease cannot be transmitted from horse to horse. several(prenominal) interesting facts put forth by the University of Missouri EPM is seen further in parts of the world that are inhabited by opossum specifically the Americas. It has been estimated that seroprevalence (indicating exposure) in Pennsylvania, Ohio, and Kentucky is as high as 50%, however only a small percentage (2-3%) of tho se exposed w untoward become ill with symptoms. Native wild birds infected are not likely to show any symptoms, however non-native birds become acutely ill and die from S. falcatula exposure. (U. Missouri 1999)Primary clinical signs of EPM occur from swelling and nerve death in the central nervous system as a result of the replicating protozoa. neurological signs can be directly referable to the site or sites of infection. The spinal cord is most often affected resulting in the three A symptoms of asymmetric ataxia and focal muscle atrophy. (Fenger, 1996) Ataxia affects the horses sense of position in space.