Peel Alison J, Bouts Tim, Flach Edmund, Rivers Sonja, Routh Andrew
Veterinary Department, Zoological Society of London (ZSL), London, United Kingdom.
J Zoo Wildl Med. 2009 Dec;40(4):773-80. doi: 10.1638/2008-0142.1.
Pituitary pars intermedia dysfunction (PPID), also known as Equine Cushing's disease, is most often diagnosed in older horses and ponies. To the authors' knowledge, there have been no reports of its diagnosis in captive nondomestic equids. A 13-yr old onager (Equus hemionus onager) at the Zoological Society of London (ZSL) Whipsnade Zoo showed clinical signs suggestive of PPID, including hirsutism, fat redistribution, weight loss, laminitis, and chronic infections. A dexamethasone suppression test was performed to confirm PPID. Subsequently, adenomatous hyperplasia and microadenoma of the pars intermedia were identified postmortem. Four months later, this onager's dam died suddenly, and adenomatous hyperplasia of the pars intermedia was diagnosed following necropsy. The dam had shown no clinical signs of PPID. Examination of archives identified eight other adult onagers that died or were euthanized between 1993 and 2007. The brain was not examined in four of these, but pituitary glands were described as enlarged during necropsy in three animals based on the subjective assessment of an experienced zoo and wildlife pathologist, making an overall prevalence of enlargement of 83.3%. Hyperplastic pituitary changes are positively correlated with age in domestic equids, and this may also be the case in onagers. Alternative etiologies are also discussed.
垂体中间部功能障碍（PPID），也称为马库兴氏病，最常发生于老龄马和矮种马。据作者所知，尚无圈养非家养马科动物患此病的诊断报告。伦敦动物学会（ZSL）惠普斯奈德动物园的一匹13岁中亚野驴（Equus hemionus onager）出现了提示PPID的临床症状，包括多毛症、脂肪重新分布、体重减轻、蹄叶炎和慢性感染。进行了地塞米松抑制试验以确诊PPID。随后，在尸检时发现中间部腺瘤样增生和微腺瘤。四个月后，这头中亚野驴的母驴突然死亡，尸检后诊断为中间部腺瘤样增生。母驴未表现出PPID的临床症状。查阅档案发现，1993年至2007年间还有另外8头成年中亚野驴死亡或被安乐死。其中4头未检查脑部，但根据一位经验丰富的动物园和野生动物病理学家的主观评估，在3只动物的尸检中发现垂体增大，总体增大患病率为83.3%。在家养马科动物中，增生性垂体变化与年龄呈正相关，中亚野驴可能也是如此。文中还讨论了其他病因。
