The acaricidal speed of kill of orally administered fluralaner against poultry red mites (Dermanyssus gallinae) on laying hens and its impact on mite reproduction

Maria D Brauneis,Hartmut Zoller,Eva Zschiesche,Anja R Heckeroth,Heike Williams

doi:10.1186/s13071-017-2534-5

Abstract

BackgroundDermanyssus gallinae, the poultry red mite, is a growing threat to chickens in poultry farms. This nocturnal hematophagous ectoparasite has a rapid rate of proliferation with a negative impact on the birds’ health, welfare and productivity resulting in severe economic consequences for poultry farmers. A study was performed with fluralaner, a novel systemic ectoparasiticide, to evaluate its effect on mite vitality and reproduction after oral administration to laying hens.MethodsSixteen healthy hens were randomly allocated to two study groups (n = 8). One group was orally treated with fluralaner by gavage at a dose of 0.5 mg/kg bodyweight twice 7 days apart. The negative control group received no treatment. Hens in each group were repeatedly infested with approximately 200 unfed adult D. gallinae at 1, 5, 8, 12, 15, 19, 22 and 26 days after the initial administration. After infestation and feeding for 2.5 h, 25 engorged mites per hen were collected and incubated in tubes. Mites were assessed for vitality (dead/live) at 4, 8, 12, and 24 h after each infestation. Tubes containing eggs and/or living mites were incubated another 8 days for assessment of mite reproductive capacity.ResultsFluralaner demonstrated a fast speed of kill in mites within 4 h post-infestation for 12 days after treatment initiation. An efficacy (mite mortality) of 98.7–100% was achieved. At 15 days after treatment initiation, 100% efficacy was achieved within 24 h post-infestation, and no mite oviposition occurred during this period. Nineteen days after treatment initiation, the mites’ ability to generate nymphs was reduced by 90.8%, which decreased to < 24.1% at later infestations.ConclusionsFluralaner administered orally to hens twice, 7 days apart, provides efficacy against experimental poultry red mite infestation for at least 2 weeks. The demonstrated rapid speed of kill results in substantial depletion of the mites’ oviposition and suggests that fluralaner can be an effective tool in the control of D. gallinae, one of the most urgent problems in poultry farms.

Highlights

Dermanyssus gallinae, the poultry red mite, is a growing threat to chickens in poultry farms
Study design This study investigated the acaricidal efficacy of fluralaner against the poultry red mite, D. gallinae, including its speed of kill and impact on mite reproduction after oral administration to hens
Mite reproduction parameters For 15 days after fluralaner administrations, 100% of mites died within 24 h following the infestation and no oviposition occurred in the fluralaner-treated group

Summary

Introduction

Dermanyssus gallinae, the poultry red mite, is a growing threat to chickens in poultry farms This nocturnal hematophagous ectoparasite has a rapid rate of proliferation with a negative impact on the birds’ health, welfare and productivity resulting in severe economic consequences for poultry farmers. Dermanyssus gallinae (De Geer, 1778), the poultry red mite, is a growing threat to chickens in poultry farms This blood-sucking ectoparasite especially affects hens in the egg-laying industry, and hobby flocks [1, 2]. The poor health condition of mite infested poultry causes major economic losses for the egg industry (estimated around €230 million per year for Europe), due to diminished egg production and poor egg quality [7]. In severe cases workers suffer amongst others from persistent skin irritation and itching dermatitis [1, 2, 10]

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