CHANGING CHEMOSUSCEPTIBILITY IN THE 2ND-STAGE LARVAE OF TOXOCARA-CANIS BY LONG-TERM INCUBATION

Second-stage larvae of Toxocara canis were maintained in vitro for one year. Susceptibility of the larvae to drugs was evaluated by means of minimal larvicidal concentration (MLC) and larval bursting percentage . MLCs of citral and decanoic acid were almost constant throughout all stages of incubation. However, bursting percentage markedly varied wi thin the first 20 weeks of incubation. Therefore, while larvae are ava ilable for use in the MLC assay at any stage of incubation, those beyo nd the first 20 weeks after incubation should be used for the bursting assay to obtain reproducible results.