RESUMO
Ivermectin administered to rabbits in drinking water (3 ml of drenching liquid (0.08% w/v ivermectin) per litre of drinking water) for one of five days, gave rise to blood levels persisting on several days and were measured by the death of mosquitoes following a meal of blood from these animals. In practice ivermectin (3 ml/l) was administered to 98 rabbits on a rabbit-meat farm for 24 hours. This treatment was repeated within a fortnight. The degree of ear mange was determined by the amount of incrustation. Within three weeks after treatment was initiated, all animals were free of crusts. Incrustation gradually recurred during the following weeks. After 161 days, approximately ten per cent of the animals showed some incrustation again. Treatment with ivermectin once every six months is advised to suppress ear mange.