Silveira Júlia A G, Passos Lygia M F, Ribeiro Múcio F B
Escola de Veterinária, UFMG, CEP 31270-901, Belo Horizonte, MG, Brazil.
Vet Parasitol. 2009 May 12;161(3-4):270-5. doi: 10.1016/j.vetpar.2009.01.028. Epub 2009 Feb 6.
Rhipicephalus sanguineus ticks are distributed throughout the world, especially in those areas in which dogs are in close contact with humans. R. sanguineus and fleas are regarded as the main ectoparasites infesting dogs in Brazil. Besides causing direct damage during the blood feeding process, this tick species can also transmit pathogens to dogs and humans. Despite its importance in Brazil, data regarding the seasonality of R. sanguineus are limited, especially with regard to natural infestations of dogs. The present study aimed to evaluate the seasonality of R. sanguineus on dogs living in Belo Horizonte, state of Minas Gerais. From August 2006 to July 2007, ticks were collected monthly from 12 adult dogs in nine houses, which were located in two districts in the north region of the city. In parallel, canine clients of a pet care department of the small animal veterinary clinic were examined for the presence of ticks before bathing and/or clipping. The climatic data recorded for Belo Horizonte during the experimental period were: mean temperature 18.6 degrees C; relative air humidity 56.5%; rainfall 37mm. The only species of ticks identified from all infested dogs was R. sanguineus, which was found in all its development stages. Among dogs living in houses, three tick population peaks were observed (August, February, and June), suggesting the occurrence of three generations per year in Belo Horizonte. A total of 7318 ticks were collected, of which 5422 were adult ticks and 1896 represented immature stages (744 larvae and 1152 nymphs). The monthly inspection of dogs living in houses demonstrated significantly higher parasitism during the dry season (p<0.05). A total of 2848 dogs from the pet care department of the small animal veterinary clinic were examined, of which 222 (7.8%) were infested with ticks and the percentage of infested dogs in the dry season was higher (p<0.05) than in the hot wet. The percentage of male dogs infested with ticks was significantly higher (58.29%) than the percentage of infested female dogs (41.70%). This study of the dynamics of R. sanguineus infestations in Belo Horizonte will contribute to establishing appropriate measures to control tick infestations in dogs.
血红扇头蜱分布于世界各地，尤其在那些狗与人类密切接触的地区。在巴西，血红扇头蜱和跳蚤被视为寄生在狗身上的主要体外寄生虫。除了在吸血过程中造成直接损害外，这种蜱类还可将病原体传播给狗和人类。尽管其在巴西很重要，但关于血红扇头蜱季节性的数据有限，尤其是关于狗的自然感染情况。本研究旨在评估米纳斯吉拉斯州贝洛奥里藏特市狗身上血红扇头蜱的季节性。2006年8月至2007年7月，每月从位于该市北部地区两个区的9所房屋中的12只成年狗身上采集蜱。同时，对一家小动物兽医诊所宠物护理部的犬类客户在洗澡和/或剪毛前检查是否有蜱。实验期间记录的贝洛奥里藏特市气候数据为：平均温度18.6摄氏度；相对空气湿度56.5%；降雨量37毫米。从所有受感染的狗身上鉴定出的蜱类仅为血红扇头蜱，且在其所有发育阶段均有发现。在居住在房屋中的狗中，观察到三个蜱虫种群高峰（8月、2月和6月），这表明在贝洛奥里藏特市每年发生三代。共采集到7318只蜱，其中5422只为成年蜱，18个96只为未成熟阶段（744只幼虫和1152只若虫）。对居住在房屋中的狗进行的月度检查显示，旱季的寄生率显著更高（p<0.05）。对一家小动物兽医诊所宠物护理部的2848只狗进行了检查，其中222只（7.8%）感染了蜱，旱季感染狗的百分比高于炎热潮湿季节（p<0.05）。感染蜱的雄性狗的百分比显著高于感染雌性狗的百分比（58.29%对41.70%）。这项对贝洛奥里藏特市血红扇头蜱感染动态的研究将有助于制定控制狗蜱感染的适当措施。
