Dynamics of the Antibody Response in Cattle Infested by <I>Hypoderma</I> (Diptera: Oestridae) After a Treatment with Injectable and Pour-on Ivermectin

Abstract

The dynamics of the anti-Hypoderma antibody response after a treatment with injectable and pour-on ivermectin against first instars of Hypoderma sp. were determined in naturally infested cows. Cattle were randomly assigned to three groups: group 1, which served as an untreated control; group 2, treated with pour-on ivermectin at a dose of 500 microg/kg of body weight, and group 3, which received 200 microg/kg of body weight of ivermectin by subcutaneous injection. Both ivermectins showed total efficacy against L-1 of Hypoderma sp. In untreated control animals, grubs became detectable in the 2 mo after treatment. Indirect enzyme-linked immunosorbent assay (ELISA) showed a significant increase in group 3 antibody levels 1 mo after treatment, whereas in group 2 the increase was not significant. Following the peak of anitibody activity in group 3, antibody levels declined at a faster rate than in those treated topically. In both treated groups, cattle remained serologically positive for 4 mo after ivermectin treatment. Thus, serological surveillance programs for cattle grubs conducted during this posttreatment period will not be influenced by treatment with ivermectin. The persistence of antibody levels after larval destruction makes the indirect ELISA unsuitable for the prediction of the efficacy of treatment.

Brief Overview of Bovine Hypodermosis in Kazakhstan and Other Central Asian Regions - With a Recommendation to Control This Parasitosis by Government Support

“…The first-choice compounds for the treatment of Hypoderma-infected cattle and yaks are currently macrocyclic lactones, such as ivermectin [36,37,38], doramectin [39,40], eprinomectin [41], and moxidectin [42,43], which have a nearly 100% efficacy against Hypoderma first-stage larvae. Depending on the formulation of the drug, they are applied either subcutaneously at a dose of 200 µg/kg bodyweight (bwt.)…”