Effects of a neem seed extract (MiteStop®) on mallophages (featherlings) of chicken: in vivo and in vitro studies.

Mallophages of birds (featherlings) are mostly very tiny and can even as adults better be recognized by their movements than by their elongate body shape when using just the naked eye. Since some species (e.g., the "shaft louse" Menopon gallinae, the elongate feather louse Lipeurus caponis, or Columbicola sp.) may pierce the pulp of feathers or the skin by their biting or scratching mandibles and thus lick the excreted blood, they may be extremely dangerous especially to young birds, even if they only feed by nibbling along the feather surface and/or eat epidermal debris. The present paper reports on the successful treatment of different races of fowls being severely infested with both above cited species. This in vivo treatment was done either by a short dipping of the whole fowl into the 1:33 dilution (with tap water) of a neem seed extract (MiteStop®) or by spraying them with the freshly diluted product. It was seen that the dead mallophages dropped down from the feathers as soon as they were dry again. As a precaution, a second treatment was done by some owners 1 week after the first one in order to eliminate all stages, which eventually might have hatched from untouched nits during the time interval between the two treatments. When controlling the treated fowls 4 weeks after the treatment, in no case (treated once or twice), living motile stages were diagnosed indicating the high efficacy of this nontoxic neem seed extract. When treating in vitro cutoff feathers contaminated with L. caponis, it was seen under the stereomicroscope, that the mallophages tried to run away from the 1:33 water-diluted active compound indicating that there is also a repellent effect. Treated L. caponis stopped leg movements within 3 min and died on their feathers within 1-20 min. Then, the last slight trembling movements of their legs and convulsions of their intestine stopped finally.