The effect of fenbendazole on the immune system of lambs

Abstract

Measurements of lymphocyte blastogenesis and antibody production were used in an immunological study to determine the effect of fenbendazole on the proliferative ability of T and B lymphocytes.

Six naive and six parasitized lambs were treated with 5mg/ kgLW of fenbendazole on days a (Trial 1) and 28 (Day 0 of trial 2), another six naive and six parasitized lambs served as controls. All 24 lambs were vaccinated against bovine virus diarrhoea mucosal disease (BVMD), the day following anthelmintic treatment (Day 1). Blood samples were collected 0, 3, 7, 14 and 21 days after anthelmintic treatment, and BVMD antibody concentration and lymphocyte proliferation response measured.

During trial 2, lymphocytes from the fenbendazole treated lambs collected on day 14 from the naive, and on days 7 and 14 from the parasitized lambs, had significantly lower lymphocyte proliferation compared to control animals, when cultured with media containing concanavalin A. Parasitized lambs also showed decreased blastogenesis 14 days after the second anthelmintic treatment when the lymphocytes were cultured in phytohemagglutinin and lipopolysacchride. Inconclusive results were obtained from the lymphocyte stimulation with ESA. Similar antibody levels were observed between the naive and the parasitized lambs.

Results indicate that fenbendazole treatment caused a reduction in T and possibly B lymphocyte proliferation, particularly in the parasitized lambs 14 days after the second drench.