Influence of anthelmintic treatment on the liveweight of outwintered ewe hoggs.

Three systems of outwintering ewe hoggs are normally practised on Scottish hill farms. A series of field trials involving some 2000 different animals was conducted to determine the response in liveweight from anthelmintic treatment for roundworms. The results suggest that, under field conditions, a strategic dosing programme using a modern anthelmintic can prevent liveweight loss in ewe hoggs wintered either on the hill or "inbye". The best response may be expected from a two dose regime--one in early winter (mid October to mid November) and the other in winter (mid January to mid February). In away-wintered hoggs, the kinder climate, better pssture, and, in the vast majority of cases, less contaminated ground, appear to outweigh the advantages of dosing after the late autumn.

Anaplasmosis: control of the first outbreak in Canada by serological identification and slaughter.

On August 13, 1968 Canada experienced its first outbreak of anaplasmosis. The initial diagnosis based on hematological and clinical evidence was made by the Provincial Veterinary Laboratory, Winnipeg, Manitoba, and later confirmed in our laboratory by use of the complement-fixation test, hematology, and animal transmission studies. Sixteen herds (1,717 cattle) were examined but the outbreak was found to be localized mainly in one herd of 830 cattle. A low degree of infection was also found in four other herds. None of the remaining 11 herds in the area were infected.The infection was controlled by serological testing, and a slaughter policy. In the four herds with low grade infection, no clinical signs were evident, and serological tests made five and six months after the discovery of the outbreak were negative. In the main herd, the tests were negative at six and nine months. Even though no clinical manifestations of anaplasmosis were detected, surveillance of the animals in the area was continued. Sera from all the cattle were tested 16 months after the initial test. Four reactors were detected in the herd in which the main infection had previously been located. In addition, single borderline reactions were observed in a herd which previously had only one questionable reactor, and in another herd which had heretofore been negative. All of these reactive animals were slaughtered including the two with low grade reactions of doubtful significance. Following the removal of the reactive animals, tests were performed until negative results were obtained twice at six week intervals. The last test was conducted at the end of January 1970, 18 months after the original test.