Dean C E, Cebra C K, Frank A A
Department of Pathology, Colorado State University, Fort Collins 80523, USA.
Vet Pathol. 1996 Nov;33(6):711-2. doi: 10.1177/030098589603300613.
Three newborn calves were affected by caudal spinal dysgenesis or agenesis (coccygeal vertebra) and persistent cloaca. The cloacas were lined by a mixture of transitional and colonic epithelium. The vertebral column of one calf was internalized into the cloaca. The association of persistent cloaca and caudal spinal anomalies is thought to be related to cell loss in the caudal cell mass, which affects caudal spinal column formation and cleavage of the cloaca by the urorectal septum. This association is well documented in humans and has been reported in Manx cats. By extrapolation, it appears likely to exist also in neonatal calves. Identification of cloacal lesions in neonatal animals should be cause for careful examination of the vertebral column because many of the associated spinal lesions are occult.
三头新生小牛受到尾椎发育不全或发育不全（尾椎）和持续性泄殖腔的影响。泄殖腔内衬有移行上皮和结肠上皮的混合物。一头小牛的脊柱内化到泄殖腔内。持续性泄殖腔与尾椎异常的关联被认为与尾侧细胞团中的细胞丢失有关，这会影响尾椎的形成以及尿直肠隔对泄殖腔的分隔。这种关联在人类中有充分记录，在曼岛猫中也有报道。由此推断，在新生小牛中可能也存在这种情况。新生动物泄殖腔病变的识别应促使对脊柱进行仔细检查，因为许多相关的脊柱病变是隐匿性的。
