Active-controlled commercial field evaluation of an independently developed fluralaner oral solution for poultry red...

Poultry red mite (Dermanyssus gallinae, PRM) remains an important ectoparasite in commercial laying-hen production, and drinking-water administration of systemic acaricides provides a practical option for whole-flock control. This study compared the field efficacy and laying performance of an independently developed 10 mg/mL fluralaner oral solution with Exzolt 10 mg/mL Solution and assessed target-animal safety and bioequivalence. A double-blind, active-controlled trial was conducted at a naturally infested commercial layer farm with a 5-row × 5-tier cage system. The products were randomly assigned to 2 independent drinking-water systems with farm-installed proportional dosing devices, with 2,400 hens monitored per area. Fluralaner was administered at 0.5 mg/kg on d 0 and d 7. Mite-trap counts, infestation severity, adverse events, and laying rate were monitored. Mean mite reduction exceeded 98% by d 1 and 99% by d 3, reached 100% by d 14, and remained above 99% through d 90. Infestation scores declined from 2.70 ± 0.67 and 2.80 ± 0.42 before treatment to 0.10 ± 0.32 and 0.20 ± 0.42 by d 7 in the test and reference areas, respectively, and were 0 from d 14 onward. Exploratory between-area comparisons detected no significant differences in mite reduction or infestation scores. Laying rate remained stable, and no treatment-related adverse events were observed. In the target-animal safety study, 80 hens received untreated water or the test product at 1 ×, 3 ×, and 5 × the recommended dose, with no consistent dose-related adverse effects identified in clinical, hematological, biochemical, pathological, production, or egg-quality outcomes. In the bioequivalence study, 66 hens received a single 0.5 mg/kg oral dose of either product. The 90% confidence intervals for the geometric mean ratios of C_max, AUC_0-t, and AUC_0-∞ were within 80% to 125%. The test product provided sustained PRM control under commercial drinking-water conditions and showed comparable systemic exposure, without evident adverse effects on laying performance, egg quality, or target-animal safety.