Abattoir survey of congenital reproductive abnormalities in ewes

A survey of abnormalities of the reproductive tract of female sheep was und ertaken at two abattoirs in the south west of England over a period of 12 m onths. During the survey, 9970 reproductive tracts from cull en es and 23,5 36 tracts from nulliparous sheep (prime lambs and hoggets) were examined. A total of 655 (6.57 per cent) ewes and 359 (1.95 per cent) nulliparous shee p had abnormalities of the reproductive tract. Of these, congenital abnorma lities of the paramesonephric ducts accounted for 2.4 per cent of the ewes and 7.4 per cent of the nulliparous sheep, congenital abnormalities of the ovaries accounted for 2.6 per rent of the ewes and 7.4 per cent of the null iparous sheep and cystic structures that were considered to have been of co ngenital origin accounted for 27.2 per cent of the eu;es and 52.7 per cent of the nulliparous sheep. The most common lesion was paraovarian cysts (26. 6 per cent of ewes and 39.0 per cent of nulliparous sheep), but few of thes e appeared to have affected the sheep's reproductive function. Several spec ific conditions were recorded, including some described for the first time in sheep. Uterus unicornis occurred in 20 sheep and other forms of segmenta l aplasia of parts of the paramesonephric ducts occurred in a further 13 an imals. Uterus didelphys occurred in six sheep, and II animals were intersex , Intersex sheep had vestigial structures that were derived from the parame sonephric ducts, hypoplastic or masculinised gonads and some had masculinis ed external genitalia. Ovarian hypoplasia occurred in 34 sheep, and in a fu rther 12 mainly nulliparous animals, the ovaries were fused. Sixty nullipar ous animals and two ewes had hydatids of Morgagni.