Field trials of a formulation containing moxidectin and 6 in 1 vaccines for sheep.

OBJECTIVE: To assess the efficacy and safety of a formulation containing moxidectin and 6 in 1 vaccine in sheep under field conditions. DESIGN: Efficacy and safety study. ANIMALS: Two hundred and five crossbred Merino lambs and two hundred and eight Merino ewes were used in the studies. PROCEDURE: A formulation was made for the simultaneous treatment of sheep with moxidectin and immunisation against clostridial diseases and caseous lymphadenitis. The efficacy against nematodes, vaccine response and safety were assessed. RESULTS: Effective control of nematodes and responses to antigens were achieved following subcutaneous administration. The formulation was safe to administer; occasional minor tissue reactions were evident, but no other adverse effects of treatment were observed in either pregnant ewes or lambs, using either the recommended dose, or an overdose of the formulation. CONCLUSION: Administration of a formulation containing moxidectin, five clostridial antigens and caseous lymphadenitis antigen proved safe and efficacious under field conditions.

Duration of the persistent activity of moxidectin against Haemonchus contortus in sheep.

Weaned lambs were infected with Haemonchus contortus 35, 28, 21, 14 and 7 days after treatment with moxidectin at 0.2 mg/kg and 35 and 14 days after treatment with ivermectin at the same dose rate. Worm counts 14 days after infection showed that moxidectin prevented the establishment of over 99% of infective larvae for 28 days and reduced the establishment rate at 35 days by 96%, relative to ivermectin. There was no difference in the protective efficacy of ivermectin at 14 or 35 days. The persistence of moxidectin is likely to provide advantages in nematode control, particularly when used as a strategic early summer treatment or as a pre-lambing treatment to ewes. Implications of the persistent activity of moxidectin for the development of resistance during the decay phase are discussed.

An evaluation of an oral formulation of moxidectin against selected anthelmintic-resistant and -susceptible strains of nematodes in lambs.

The efficacy of an oral formulation of the newly developed parasiticide, moxidectin, was tested against benzimidazole-resistant Haemonchus contortus, Trichostrongylus colubriformis, and Nematodirus spathiger, levamisole-resistant Ostertagia circumcincta, and susceptible Cooperia curticei infections in weaned lambs. Thirty-two lambs were experimentally infected with mixed doses of the above strains of nematodes. They were allocated into four treatment groups by stratified randomisation using liveweights and faecal egg counts 28 days later. One group received moxidectin at 0.2 mg/kg liveweight, one group oxfendazole at 4.5 mg/kg liveweight, one group levamisole at 7.5 mg/kg liveweight and the last group remained untreated as the control. Worm burdens in the lambs at slaughter 10 days after oral treatment confirmed the resistance status of the nematode strains used, and showed that moxidectin had a greater than 99.9% efficacy (p<0.01) against all of them. No adverse effects due to treatment with moxidectin were observed in any of the animals.

Proximal femoral osteotomy: a trigonometric analysis of effect on leg length.

A trigonometric analysis of the effect of a proximal femoral osteotomy, either dome or cuneiform, on leg length was done to aid the preoperative planning for this surgery. Change in leg length may be determined for a dome osteotomy by multiplying the length of the head-neck segment by the difference between the cosines of the preoperative and postoperative neck-shaft angles as measured from the vertical. A series of determinations are tabulated for a variety of head-neck lengths and angulation changes. When a cuneiform osteotomy is being done, the effect of the wedge can be determined and should be considered. Also to be considered are a tendency for spontaneous correction and growth stimulation from the osteotomy.