Efficacy of ivermectin against Setaria microfilariae in calves and cerebrospinal setariosis in sheep and goats.

Ten calves harboring microfilariae (Mf) were injected with ivermectin at a single dose of 200 micrograms/kg body weight. Thereafter, the number of calves harboring Mf was gradually reduced to 7, 2 and 0 by 1, 4 and 12 weeks, respectively and remained negative for microfilariae by 16 weeks after injection. Furthermore, none of 221 goats and sheep injected twice with ivermectin at a dose of 200 micrograms/kg body weight developed setariosis while 17 out of 303 non-injected animals suffered from that disease. Therefore, ivermectin was much effective for the eradication of Mf in calves and the prevention of setariosis in sheep and goats.