Vaginal biopsy as a method for diagnosing pregnancy in the ewe
Mitchell, D.
Veterinary Record 91(7): 161-165
1972
ISSN/ISBN: 0042-4900 PMID: 5073606 Document Number: 44996
Histological examination of 863 vaginal biopsy sections taken from 554 ewes revealed a gradual change from a stratified squamous type of epithelium in the normal non-pregnant cycling animal to epithelium, in the pregnant ewe, in which the surface stratified cells were replaced by cuboidal cells with vesicular nuclei and pale-staining cytoplasm. This change was usually associated with a non-significant reduction in the number of epithelial cell layers. These histological changes appear to be related to ovarian activity. Using this technique to diagnose pregnancy, correct interpretations were obtained in 89.2% of pregnant ewes after the 50th day of gestation; 6.0% were inconclusive and 4.8% were incorrect. In non-pregnant ewes, the interpretations were 79.3% correct, 11.2% inconclusive and 10.5% incorrect. In a group of pregnant ewes in which mating was observed and dates recorded, 93.1% were correctly diagnosed after the 40th day of gestation.