INFESTATION POTENTIAL OF PSOROPTES-OVIS (HERING) FROM CATTLE INJECTED WITH IVERMECTIN

Abstract

Cattle scabies mites, P. ovis (Hering), surviving on cattle injected s.c. with ivermectin [from Steptomyces avermitilis], were capable of infesting to unprotected cattle 3, 5, 7, and 9 days after injection. All recipient cattle exposed to mites from vehicle-injected cattle developed reproductive colonies in 5 wk. All recipient cattle exposed to mites from ivermectin-injected cattle at 3 and 5 days after injection developed reproductive colonies in 5 wk. By 8 wk, 3 of 4 and 2 of 4 recipient cattle exposed to mites from ivermectin-injected cattle 7 and 9 days after injection, respectively, developed reproductive colonies. To prevent the spread of mites, injected cattle should be isolated from uninfested cattle for longer than 9 days.