Published online by Cambridge University Press: 27 March 2009
Previous work has shown that the technique of laparoscopy in anaesthetized ewes is a practical and reasonably accurate method for the diagnosis of pregnancy between 17 and 28 days after conception and for estimating numbers of foetuses (Phillippo et al. 1972). This method in common with other reported endoscopic techniques for sheep positions the animal on its back, necessitating the use of either general anaesthesia (Roberts, 1968; Boyd & Ducker, 1973) or tranquillization and local anaesthesia (Kelly & Allison, 1976). These methods have the disadvantages of the necessity to withhold food and water for up to 24 h prior to surgery and the risk associated with general anaesthesia and the positioning of the animal. A new procedure with the sheep standing was therefore developed from the method used in cows (Mariana, 1969; Wishart & Snowball, 1973).