Faull W B, Clarkson M J, Winter A C
Vet Rec. 1986 Nov 15;119(20):491-3. doi: 10.1136/vr.119.20.491.
Toxoplasmosis was thought to be a minor problem on a lowland sheep farm purchasing some 200 ewe lambs annually. Serological investigations and production records suggested a more substantial problem with most of the ewe lambs seroconverting during their first pregnancy, many while still at grass and receiving no supplementary food. Only 60 live lambs were produced per 100 ewe lambs tupped. It was known that cats occasionally inhabited the sheep houses, from which straw bedding was spread onto the pastures after lambing. Trials over two years with ewe lambs grazing either 'clean' or 'dirty' pastures indicated that the straw bedding was the most likely source of infection. Serial serological studies not only defined the time of infection but also showed that the ewe lambs could be kept free of infection and produce more live lambs; 58 live births came from 81 'clean' ewe lambs compared with 21 from 50 'dirty' ewe lambs.
弓形虫病在一个每年购进约200只母羊羔羊的低地养羊场曾被认为是个小问题。血清学调查和生产记录表明存在一个更严重的问题，即大多数母羊羔羊在首次怀孕时血清转化，许多在仍在放牧且未接受补充饲料时就已感染。每100只配种的母羊羔羊仅产出60只活羔羊。已知猫偶尔会进入羊舍，产羔后羊舍里的褥草会被铺到牧场上。对在“干净”或“脏污”牧场放牧的母羊羔羊进行的为期两年的试验表明，褥草最有可能是感染源。连续的血清学研究不仅确定了感染时间，还表明母羊羔羊可以避免感染并产出更多活羔羊；81只“干净”母羊羔羊中有58只活产，而50只“脏污”母羊羔羊中只有21只活产。
