Publications (3)3.47 Total impact
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Article: Hepatic capillariasis in a Cape ground squirrel (Xerus inaurus).
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ABSTRACT: We report, for the first time, an incidental finding of Calodium hepaticum infestation in a sub-adult female Cape ground squirrel (Xerus inaurus). Post mortem examination of the squirrel revealed severe haemoperitoneum, splenomegaly and hepatomegaly with miliary white spots distributed diffusely throughout the hepatic parenchyma. Histologically the portal tracts in the liver showed granulomatous inflammation with fibrosis and numerous giant cells. Occasional adult worms were identified and there were multiple C. hepaticum eggs distributed diffusely throughout the portal tracts and the parenchyma. The spleen also contained C. hepaticum eggs. The genus Rattus is the primary host and reservoir of C. hepaticum, but C. hepaticum infections have been reported previously in other Sciuridae. Based on our findings, people should be cautious of the zoonotic potential of C. hepaticum, when they come into contact with the Cape ground squirrel.Journal of the South African Veterinary Association 12/2009; 80(4):276-7. -
Article: Shearing at the end of summer affects body temperature of free-living Angora goats ( Capra aegagrus) more than does shearing at the end of winter.
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ABSTRACT: Angora goats are known to be vulnerable to cold stress, especially after shearing, but their thermoregulatory responses to shearing have not been measured. We recorded activity, and abdominal and subcutaneous temperatures, for 10 days pre-shearing and post-shearing, in 10 Angora goats inhabiting the succulent thicket of the Eastern Cape, South Africa, in both March (late summer) and September (late winter). Within each season, environmental conditions were similar pre-shearing and post-shearing, but September was an average 5°C colder than March. Shearing resulted in a decreased mean (P < 0.0001), minimum (P < 0.0001) and maximum daily abdominal temperature (P < 0.0001). Paradoxically, the decrease in daily mean (P = 0.03) and maximum (P = 0.01) abdominal temperatures, from pre-shearing to post-shearing, was greater in March than in September. Daily amplitude of body temperature rhythm (P < 0.0001) and the maximum rate of abdominal temperature rise (P < 0.0001) increased from pre-shearing to post-shearing, resulting in an earlier diurnal peak in abdominal temperature (P = 0.001) post-shearing. These changes in amplitude, rate of abdominal temperature rise and time of diurnal peak in abdominal temperature suggest that the goats' thermoregulatory system was more labile after shearing. Mean daily subcutaneous temperatures also decreased post-shearing (P < 0.0001), despite our index goat selecting more stable microclimates after shearing in March (P = 0.03). Following shearing, there was an increased difference between abdominal and subcutaneous temperatures (P < 0.0001) at night, suggesting that the goats used peripheral vasoconstriction to limit heat loss. In addition to these temperature changes, mean daily activity increased nearly two-fold after March shearing, but not September shearing. This increased activity after March shearing was likely the result of an increased foraging time, food intake and metabolic rate, as suggested by the increased water influx (P = 0.0008). Thus, Angora goats entered a heat conservation mode after shearing in both March and September. That the transition from the fleeced to the shorn state had greater thermoregulatory consequences in March than in September may provide a mechanistic explanation for Angora goats' vulnerability to cold in summer.animal 07/2009; 3(7):1025-36. · 1.74 Impact Factor -
Article: Effects of desertification on the body temperature, activity and water turnover of Angora goats
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ABSTRACT: Globally, pastoral practices have transformed habitats, which often lead to desertification. With climate change predicted to exacerbate desertification, adaptation provides the best survival strategy for agriculturally important herbivores. We investigated body temperature, water turnover, physical activity and microclimate selection of Angora goats inhabiting transformed and intact sites in the Eastern Cape Province, South Africa. Although goats on both sites responded similarly under most environmental conditions, when goats were subjected to a thermal stress, imposed by shearing, those inhabiting the transformed site had a faster rate of rise in abdominal temperature (0.38 versus 0.31 °C h−1, P = 0.0009), displayed an increased 24-h abdominal temperature amplitude (1.8 versus 1.6 °C, P = 0.01) and were generally less active (3.9 versus 5.2 activity units) compared to goats inhabiting the intact site. Post-shearing, goats inhabiting the transformed site had higher water turnover rates (P < 0.0001) and selected more variable microclimates (P < 0.0001) than goats inhabiting the intact site, despite obtaining less water from their diet (P = 0.01). Goats inhabiting the transformed site were more water dependent and more susceptible to thermal stresses in their environment than were those inhabiting the intact site. Coping with thermal challenges will be essential for Angora goats if the mohair industry is to thrive under future climate change scenarios.Research highlights► Angora goats exposed to the desertified site were susceptible to thermal stresses. ► Goats inhabiting the desertified site were exposed to more variable microclimates. ► Goats on the desertified site were more water dependent than those on the intact site. ► Physiological measurements can improve our understanding of herbivore adaptability.Journal of Arid Environments 75(1):20-28. · 1.72 Impact Factor
