GLOSSARY

Words followed by this symbol are defined here

anthrax--- potentially fatal infectious disease characterized by fever, throat swelling and enlarged spleen; now rare in horses. antigen--- substance, often a protein, that the body’s immune system recognizes as foreign and reacts to by producing an antibody. arthritis--- inflammation of a joint. ataxia--- incoordination of the muscles, which results in shaky, irregular movements; may also be accompanied by weakness and loss of proprioception. botulism--- food poisoning caused by the toxin secreted by Clostridium botulinum bacteria, which can contaminate feed or water; characterized by paralysis, beginning with the muscles of swallowing; usually fatal. choke--- in horses, obstruction of the esophagus; in people, obstruction of the windpipe (trachea). disunited canter--- occurs when a horse’s gait is not synchronized correctly, moving on one lead in the front legs and the other in the hind legs. electrolytes--- simple inorganic compounds that dissolve in water and are essential for many of the chemical processes in the body. endotoxemia--- presence of specific bacterial poisons (endotoxins) in the blood; usually caused by severe colic and resulting in shock and/or laminitis. equine herpesvirus (EHV)--- a family of viruses that primarily cause chronic respiratory infec- tions in horses (EHV-1, EHV-4). EHV-1 can also cause abortions in mares and, in rare cases, both EHV-1 and -4 can cause neurological signs, including progressive weakness and incoordination. EHV-3 causes a venereal disease called equine coital exanthema. equine viral arteritis--- respiratory and venereal disease that can cause abortion. fecal egg count--- laboratory procedure for determining the number of internal-parasite eggs in a fecal sample; used primarily to estimate a horse’s level of infection with ascarids and/or strongyles. hyaluronic acid (HA)---molecule that forms the basis of the lubricating fluid within joints as well as connective tissues throughout the body. hydrocephalus--- abnormal amount of fluid beneath the skull, resulting in an enlarged head, brain atrophy and mental deterioration. influenza--- acute viral infection involving the respiratory tract. Influenza is marked by inflammation of the nasal mucosa, the pharynx, the conjunctiva, the lungs and sometimes the heart muscle. insulin resistance--- metabolic disorder, similar to type-2 diabetes, that occurs when certain cells in the body become less sensitive to the action of insulin, and normal amounts of the hormone can no longer keep adequate amounts of glucose moving into the cells for use as fuel. laminitis--- inflammation of the sensitive plates of soft tissue (laminae) within the horse’s foot caused by physical or physiologic injury. Severe cases of laminitis may result in founder, an internal deformity of the foot. Acute laminitis sets in rapidly and usually responds to appropriate, intensive treatment, while chronic laminitis is a persistent, long-term condition that may be unresponsive to treatment. linebreeding--- breeding two related individuals, usually at least two to three generations removed, to intensify the inheritance from a particular ancestor. pituitary pars intermedia dysfunction (PPID, Cushing’s disease)---disease caused when the cortex of the adrenal gland produces excessive amounts of hormones, including cortisol; signs include persistent long hair, thin skin, fragile bones, stupor, weakness and sweating. polysulfated glycosaminoglycans (PSGAGs)--joint-lubricating substances that are chemically similar to the fluid-producing components of cartilage. When injected intramuscularly or directly into a joint, PSGAGs stimulate the production of synovial fluid. Potomac horse fever (monocytic ehrlichiosis) ---disease caused by a rickettsial organism, Neorickettsia risticii. Named after the Potomac River Valley where it was first recognized in 1979, the disease is characterized by fever, diarrhea and laminitis. strangles (distemper)---highly contagious infection of the lymph nodes, usually of the head, caused by Streptococcus equi bacteria. The abscesses may become so large as to obstruct the airway (hence the term “strangles”) and may break internally, draining a thick, yellow pus through the nose, or externally, draining through a spontaneous or surgical opening in the skin. windswept legs--- conformation abnormality in which both legs (either the fore or the hind) are “bent” to the side in one direction.