AFTER TROPICAL CYCLONE DINEO, AN INCREASED MORTALITY IN SHEEP AND GOATS FROM HAEMONCHUS CONTORTUS AT BOTSWANA UNIVERSITY OF AGRICULTURE AND NATURAL RESOURCES (BUAN) FARM

Abstract

An investigation was carried out to determine the cause of increased mortality in sheep and goats at BUAN farm in March 2017. At the time of reporting sheep and goat deaths had occurred daily for over a week. Clinical signs included weakness, dullness, poor body condition, recumbence followed by death. The investigation consisted of physical examination of sick animals and post mortem examinations. Also abomasal worm counts were carried out on two adult animals and a kid. Additionally, 32 randomly selected goats were tested for gastrointestinal nematodes using faecal egg count (FEC). Another group of animals consisting 12 sheep (6 adults and 6 lambs) and 12 goats (6 adults and 6 kids) were monitored for FEC for six weeks to compare sheep with goats and adults with young animals. A review of meteorological data proceeding the case was carried out. Examined animals were diagnosed with Haemonchus contortus characterised by poor body condition, weakness, pale mucous membranes and the so-called bottle jaw. Abomasal worm counts ranged from 400 in the kid to 1900 in an adult. A cohort of 32 goats had FEC of 6544±1081 (Mean ±SEM) eggs per gram (EPG) and 95% confidence interval: 4,339 - 8,748 EPG. FEC of both sheep and goats increased over a six week period with the increase in sheep exceeding that in goats. The pattern of FEC increase was similar between adults and young animals. Meteorological data indicated above average rainfall with percentage departure from normal rainfall at 100% for the affected area. Tropical cyclone Dineo brought an unusually high amount of rain in midFebruary 2017 preceding the case. It is concluded that an above average rainy season precipitated a Haemonchus contortus outbreak in sheep and goats at BUAN farm.