Safety of fluralaner oral solution, a novel systemic poultry red mite treatment, for chicken breeders’ reproductive performances

Abstract

BackgroundPoultry mites are the most significant pest affecting production systems in the chicken egg-laying industry, altering the health condition of the birds, and causing stress, mortality and decline of egg quality impacting economic performance. Fluralaner is a novel systemic parasiticide that is effective against poultry mites (Dermanyssus gallinae, Ornithonyssus sylviarum) in chickens after oral administration. The evaluation of the safety of this new product in breeder chickens is particularly relevant because poultry mite infestation affects long cycle production systems, such as layers and breeders farms, for which the productivity heavily depends on the health of the reproductive function. This study was designed to investigate the safety for reproductive performances of fluralaner in male and female chickens at 3 times the recommended dose (1.5 instead of 0.5 mg/kg body weight) and 2 times the recommended duration (4 administrations instead of 2 administrations, with a 7 day interval between administrations).MethodsThis randomized, parallel-group, blinded study included 432 Bovans brown parent stock chickens (48 males and 384 females, 17-week old). Birds were randomly assigned to 16 pens (three males and 24 females per pen), and then each pen assigned to one of the two treatment groups (8 pens, i.e. 216 birds per group). Fluralaner was administered via drinking water on a total of four occasions 7 days apart, at daily doses of 1.5 mg fluralaner/kg body weight, equivalent to 3 times the recommended dose of fluralaner per administration and 2 times the recommended number of administrations. Birds supplied with non-medicated drinking water served as controls. The treatments were given at time of peak egg production in the bird’s life: i.e. at 30 to 34 week of age. During that period, all adult chickens were clinically observed. The reproductive performances were carefully monitored including the number of eggs laid, egg weight, fertility and hatchability. Furthermore, the health and viability (up to 14 days of life) of randomly selected chicks was also monitored.ResultsThere were no clinical findings related to fluralaner treatment. There were no statistically significant differences between the reproductive performances of treated and control groups, nor in their progeny chickens viability.ConclusionsOral administration of fluralaner was well tolerated by breeder chickens with a safety margin of approximately 3-fold obtained. Fluralaner had no effect on the egg number, weight and fertility, and no effect on egg hatchability or chick viability. Based on these results, a safe use of the new mite treatment proposed with fluralaner administered via drinking water is expected in layer and breeder field industrial conditions.

Lethal and sublethal effects of fluralaner on the two‐spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae)

“…Fluralaner has high activity towards parasitic mites on animals, such as demodectic mite ( Demodex sp.) on Shih‐Tzu Canis lupus dingo Meyer and red‐handed tamarins Saguinus midas , poultry red mite Dermanyssus gallinae in birds, and northern fowl mite Ornithonyssus sylviarum in laying hens . In addition, fluralaner also exhibits high activity towards the phytophagous mite of TSSM and has been shown to bring about 100% mortality at a concentration of 3.1 mg L −1 against fipronil‐resistant (∼ 500 mg L −1 ) TSSM …”

“…on Shih-Tzu Canis lupus dingo Meyer 18 and red-handed tamarins Saguinus midas, 19 poultry red mite Dermanyssus gallinae in birds, 20 and northern fowl mite Ornithonyssus sylviarum in laying hens. [21][22][23] In addition, fluralaner also exhibits high activity towards the phytophagous mite of TSSM and has been shown to bring about 100% mortality at a concentration of 3.1 mg L −1 against fipronil-resistant (∼ 500 mg L −1 ) TSSM. 24 As is well-known, research on the toxicological effects of fluralaner towards TSSM will enhance the ability to design and execute mite management programs.…”

Effect of oral afoxolaner on naturally occurring infestations of peacocks by the louse Goniodes pavonis

“…Prior evidence that the isoxazolines would be effective against lice was reported in a study of dogs naturally infested with the sucking louse Linognathus setosus . Several prior studies that used isoxazolines in poultry also supported the potential efficacy and safety of an isoxazoline against ectoparasites on birds …”

“…The mechanism of action of the isoxazolines is inhibition of chloride channels dependent on glutamate and gamma‐aminobutyric acid (GABA) . Drugs in this class have been used successfully in exotic animals for the treatment of a variety of insect and mite infestations . In poultry, isoxazolines have been well‐tolerated and shown to have a high margin of safety for oral dosing .…”

“…Drugs in this class have been used successfully in exotic animals for the treatment of a variety of insect and mite infestations . In poultry, isoxazolines have been well‐tolerated and shown to have a high margin of safety for oral dosing . There are no reports of the use of afoxolaner in exotic or ornamental birds.…”