Ingestion of host antibodies by Bovicola ovis on sheep

Sheep body lice, Bovicola ovis, collected from moderately heavy infestations on Merino wethers, were assayed by ELISA for their content of host-derived specific immunoglobulin (Ig). Relative concentrations of anti-horse myoglobin antibodies in the lice and in sera from their hosts were used to estimate the total quantities of functional Ig (that which remained capable of binding specifically to its antigen) present, giving a mean of 0.21 +/- 0.20 mg/g of lice. An attempt to demonstrate the presence of antibodies against B. ovis antigens in naturally-infested host sheep using ELISA produced inconclusive results. The implications of the quantities of Ig ingested by feeding B. ovis are discussed in relation to the feasibility of immunological control of this species on sheep.