Contagious Diseases

Any horse which is sick and suspected of having a contagious disease should be immediately isolated from the healthy stock. If possible, a single person should be assigned to the care of this animal, and that person should be educated to use proper
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"A serious epidemic of a nature still unknown is going on in the region of two of our plantations. Area of Yambuku is declared highly dangerous. All movement in and out of Yambuku is forbidden. Burn all linen in contact with the sick. Do not cross this barrier or you will die."

"The mission of Yambuku, with its schools, farms, and hospital, was still an island of efficiency and commitment in the midst of a dense, rain-soaked forest. At the end of August 1976, a lethal hemorrhagic disease, later known as Ebola fever, exploded out of the Yambuku hospital, devastating the mission and surrounding villages. An oasis of peace and order became a focus of terror and death."–William T. Close, MD

Anyone who has endured an epidemic of strangles in a group of young horses, experienced the devastation of a herpes virus-induced "abortion storm," or suffered through an outbreak of Salmonella knows the importance of understanding some of the nuances of contagious disease. The three diseases that will be discussed here are salmonellosis, herpes virus infection (rhinopneumonitis and encephalomyelitis), and Streptococcus equi infection (strangles). There are other contagious diseases, but these probably represent the three that have the greatest impact in North America. Although these three will be discussed in detail, the principles of prevention and containment are essentially the same for reducing the spread of most diseases.

It is extremely important that before discussing disease, certain medical terminology is accurately understood. There are many terms regarding the spread of disease that are used incorrectly and therefore alter the meaning, thus preventing a "true" understanding of the disease process. Words that are frequently misused are: infection vs. infectious vs. infective vs. contagious vs. contagion; and endemic vs. epidemic vs. outbreak

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Written by:

Michael A. Ball, DVM, completed an internship in medicine and surgery and an internship in anesthesia at the University of Georgia in 1994, a residency in internal medicine, and graduate work in pharmacology at Cornell University in 1997, and was on staff at Cornell before starting Early Winter Equine Medicine & Surgery located in Ithaca, New York. He was an FEI veterinarian and worked internationally with the United States Equestrian Team. He died in 2014.

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