ABSTRACT
Four trials including 11,266 sheep were conducted in South Africa to evaluate the efficacy of the systemic parasiticide ivermectin against field outbreaks of sheep scab (Psoroptes ovis) when two doses of approximately 200 micrograms/kg were administered subcutaneously seven days apart (days 0 and 7). As sheep scab is a notifiable disease in South Africa, it was not possible to include an untreated control group. The prevalence of clinically affected animals in the four treated flocks varied from 0.4 per cent to 99 per cent before the two treatments. After the treatments, there were no signs of active clinical infection in any of the sheep between days 28 and 30, or at subsequent examinations. P ovis mites were recovered from scrapings from 114 of 127 indicator sheep before the treatment but no mites were recovered from them between days 28 and 30 or 42 and 58 after the treatments.
Subject(s)
Disease Outbreaks/veterinary , Ivermectin/therapeutic use , Mite Infestations/veterinary , Sheep Diseases/drug therapy , Animals , Female , Male , Mite Infestations/drug therapy , Mite Infestations/epidemiology , Mites/isolation & purification , Sheep , Sheep Diseases/epidemiology , Skin/parasitology , South Africa/epidemiologyABSTRACT
Acute deaths occurred in 47 out of a total of 131 imported psittacine birds whilst in quarantine. Few and non-specific clinical signs were seen during the course of the disease outbreak, but gross pathology revealed severe hepatomegaly and splenomegaly. A herpes virus was isolated from liver and spleen material taken from 2 birds, an Amazon (Amazona aestiva aestiva) and a Yellow-collared macaw (Ara auricollis). Identification procedures included virus neutralisation tests carried out in chicken embryo fibroblast cultures. Neutralisation of the virus was obtained by antisera to Psittacid herpesvirus type 1 (HV1) but not against HV2 or HV3.
