After the diagnosis of acute Crotalaria retusa poisoning, 21 healthy sheep from the affected flock were returned to the paddock and continued to consume the sprouting plants. Two years after returning these sheep to the paddock, very few plants were still alive, and after 3 years, no C. retusa plants were observed. The sheep had neither clinical signs nor biochemical alterations and delivered healthy lambs. It is concluded that resistant sheep can be used for the biological control of C. retusa.

No abstract

Pesq. Vet. Bras. 32(6) The skin of the affected sheep was whitish, irregularly thickened, with alopecia, crusts, and intense pruritus. Those lesions were localized more frequently in the head (ears and periocular and frontal regions) but in some animals the dorsum and croup were also affected. Histologic lesions of the epidermis were hyperkeratosis, acanthosis, hypergranulosis, and moderate spongiosis. The dermis showed inϐiltration by eosinophils, macrophages and plasma cells, mainly perivascular. The hair follicles showed keratosis and the sudoriparous glands were dilated. No changes were observed in the differential blood count. In April and June 2010 insects were captured by the use of CDC light trap. Forty three out of 110 dipterous captured were identiϐied as Culicoides insignis Lutz. It is concluded that the disease is a seasonal allergic dermatitis associated with C. insignis bites. A pele apresentava lesões alopécicas, crostosas, enrugadas, esbranquiçadas e com intenso prurido, localizados na região da cabeça (orelhas, ao redor dos olhos e região frontal), região dorsal do corpo e garupa. Histologicamente, a epiderme apresentou hiperqueratose, acantose, hipergranulose e moderada espongiose. Na derme havia