RESUMO
Fifty Bos taurus x Bos indicus heifers naturally infested with Boophilus microplus ticks were divided into two groups of 25 heifers each. Individuals of one group were treated with moxidectin 0.5% pour-on at a dosage of 500 microg of moxidectin/kg body weight and heifers from the other group remained as untreated controls. An efficacy higher than 95% was found on days 7-21 after treatment by using female ticks 4.5-8.0 mm long as the main infestation parameter. A lower, but significant efficacy (p < 0.05) was also found on days 1 (32.3% efficacy) and 27 (73.4% efficacy) post-treatment. Significantly (p < 0.05) lower numbers of immature ticks were also observed on heifers of the treated group from days 7 through 27 after treatment. A lower engorgement weight of female ticks from treated heifers was found on days 1 and 21 after treatment. Treatment also affected reproductive performance (oviposition, egg hatch and number of eggs laid) of female ticks collected on Day 1.
Assuntos
Doenças dos Bovinos/prevenção & controle , Inseticidas/farmacologia , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Administração Tópica , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Argentina , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Inseticidas/administração & dosagem , Inseticidas/uso terapêutico , Macrolídeos , Oviposição/efeitos dos fármacos , Infestações por Carrapato/prevenção & controle , Carrapatos/fisiologiaRESUMO
The hematophagous sucking louse Microthoracius mazzai Werneck, 1932, is redescribed and identified as a parasite of alpacas, Lama pacos L. Specimens were collected on animals 10-14 mo old, located on a large community farm at 4,600 m above sea level in the Peruvian Andes. In total, 26 scanning electron microscope (SEM) figures are included that highlight salient and differential characteristics, especially the unique elongated spindle-shaped head, which is almost as long as its abdomen. Alpacas, 1 of the 4 species of South American camelids, are important for their production of high-quality wool in the Andes Mountain range countries, especially Peru and Bolivia; to a lesser degree Chile; and more recently Argentina, where breeding and disease control programs are receiving increased technical support. Information is given on the prevalence of lice infestations in the flock, clinical signs, and economic losses. We report the efficacy of moxidectin (SC, 200 mcg/kg, b.w.) in a repeated treatment program of 7-10 d, which is currently used for mange control in these ruminants.