Madigan J E, Valberg S J, Ragle C, Moody J L
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
J Am Vet Med Assoc. 1995 Jul 1;207(1):74-6.
Severe muscle cramping not associated with exercise was observed in 5 horses. Focal muscle groups in various regions underwent intermittent visible contraction. Intermittent prolapse of the third eyelid, sweating, pawing, muscle tremors, and muscle fasciculations also were observed. Clinical signs often were misconstrued as signs of colic. Percussion of muscle induced contraction of muscle groups. Concentrations of serum electrolytes and the acid-base balance were within reference limits, but activities of creatine kinase and aspartate transaminase were moderately high. Muscle biopsy revealed no abnormalities except for a few necrotic muscle fibers undergoing phagocytosis. Electromyography of 1 horse was suggestive of increased motor unit activity. All horses had Otobius megnini (ear tick) infestations and had recurrence of signs until treatment was initiated for ear ticks.
在5匹马中观察到与运动无关的严重肌肉痉挛。不同区域的局部肌肉群出现间歇性可见收缩。还观察到第三眼睑间歇性脱垂、出汗、刨地、肌肉震颤和肌束震颤。临床症状常被误解为绞痛症状。叩击肌肉会引起肌肉群收缩。血清电解质浓度和酸碱平衡在参考范围内，但肌酸激酶和天冬氨酸转氨酶活性中度升高。肌肉活检除少数坏死肌纤维正在被吞噬外未发现异常。对1匹马进行肌电图检查提示运动单位活动增加。所有马匹均感染了巨耳蜱（耳蜱），在开始治疗耳蜱之前症状反复出现。
