Effects of treatment with topical ivermectin three and eight weeks after turnout on nematode control and the performance of second-season beef suckler cattle.

Two groups of yearling suckled beef calves born between January and May of the preceding year and another two groups of lighter and slightly younger calves born between the previous March and July were grazed during their second year on four separate paddocks known to be contaminated with infective larvae of gastrointestinal nematodes. One of the heavier and one of the lighter groups were treated with a topical formulation of ivermectin three weeks and eight weeks after turnout. The treatment of the heavier group had only relatively minor parasitological effects and no effect on weight gains, whereas the treatment of the lighter cattle resulted in increased weight gains due to effective nematode control. The paper highlights that small differences in previous performances, age and exposure to parasites can have a substantial impact on the benefits accrued from anthelmintic treatment.

A survey of benzimidazole resistant nematodes in sheep in three countries of southern England.

Faecal samples were collected from 209 randomly selected sheep farms in southern England, and the nematode eggs extracted were tested by an egg hatch assay and by a larval development test for their resistance to benzimidazoles. Benzimidazole resistance was found on 35 per cent of farms tested in East Sussex, 44 per cent in Oxfordshire and 61 per cent in West Sussex.

Topically applied ivermectin: efficacy against torsalo (Diptera: Cuterebridae).

To determine the systemic efficacy and persistence of a 0.5% ivermectin topical formulation against natural infestation of torsalo, Dermatobia hominis (L., Jr.), larvae in cattle, two trials in Colombia and two trials in Brazil were done. Of 56 infested cattle used in these trials, 28 were treated and 28 served as untreated controls. The formulation was poured along the back of each animal at a rate of 0.5 mg (AI)/kg body weight. Significantly fewer larvae were counted in the treated animals than on controls on days 9 and 10; greater than 99% control resulted. The first reinfesting larvae were observed in a few animals on days 30 and 31.

A skeletal growth defect in the puma (Felis concolor).

Clinical and radiological signs shown by a young deformed puma cub, and the pathological findings following its euthanasia at eight months, are presented. These findings do not resemble those in the recognised nutritional bone diseases of the growing carnivore, but closely resemble an hereditary disease of the dog and, at least in one respect, an hereditary disease in man. This case may be an example of hereditary chondrodysplastic dwarfism in the puma. An unusual finding was the presence of iron in the cartilage of abnormal growth plates.