Stegelmeier B L, James L F, Hall J O, Mattix M T
USDA/ARS Poisonous Plant Research Laboratory, Logan, Utah 84341, USA.
Vet Hum Toxicol. 2001 Oct;43(5):302-4.
About 200/2500 Spanish goats foraging on mountain rangelands of western Montana developed neurologic disease with severe rear limb weakness, knuckling of the rear fetlocks, and a hopping gait. Sick goats were of all ages and in good flesh, though they often had dull, shaggy coats. Some mildly affected animals recovered after being moved to feed lots, but others progressed to recumbency, seizures and death. At necropsy both moribund and clinically affected animals had few gross lesions; 1 animal had contusions and puncture wounds on rear legs and perineum, suggestive of predator bites. Histologic lesions included mild vacuolation of neurons and visceral epithelial cells, mild diffuse cerebral edema with minimal neuronal pyknosis, and random, multifocal Wallarian degeneration of spinal cord axons. Affected animals had elevated serum sodium, potassium and chloride levels; other mineral analyses and serum biochemistries were within normal limits. Locoweed-induced depression and inhibition of neuromuscular function coupled with water deprivation due to predation pressure allowed development of neurologic disease and hypernatremia.
大约200/2500只在蒙大拿州西部山区牧场觅食的西班牙山羊患上了神经系统疾病，出现严重的后肢无力、后蹄关节屈曲和跳跃步态。患病山羊年龄各异，膘情良好，不过它们的被毛往往暗淡、粗糙。一些受轻度影响的动物被转移到饲养场后康复，但其他动物则发展为卧地不起、癫痫发作并死亡。尸检时，濒死和临床受影响的动物几乎没有肉眼可见的病变；1只动物后腿和会阴部有挫伤和穿刺伤，提示可能遭到捕食者咬伤。组织学病变包括神经元和内脏上皮细胞轻度空泡化、轻度弥漫性脑水肿伴轻微神经元核固缩，以及脊髓轴突随机、多灶性瓦勒变性。患病动物血清钠、钾和氯水平升高；其他矿物质分析和血清生化指标均在正常范围内。疯草引起的抑郁和神经肌肉功能抑制，加上因捕食压力导致的缺水，使得神经系统疾病和高钠血症得以发展。
