Incidência e distribuição de Amblyomma cajennense em regiões corporais de eqüinos das raças Mangalarga Marchador e Bretão Postier, naturalmente infestados

Abstract

The objective of this study is to verify the incidence and the distribution of the tick Amblyomma cajennense tick in some infected regions of equines'body. Fifteen animals, 8 mares and 7 colts from Mangalarga Marchador and Bretão Postier races, raised in the Zootechny Institute Farm, Federal Rural University of Rio de Janeiro, were selected. From July, 1996 to May, 1997 (every 21 days) the animals were submitted to examination, mapping and ingurgitated females countig in 14 previously determined regions: face, lower jaw, neck, breast, shoulder-blade, armpits, former limbs, womb, back, flank, hip, udder, posterior limbs and perianal. The observed regions were classified in: anterior, posterior, median, right side and left side. The deviation analysis was made taking into account a random blocks delineation, whose scores were previously transformed on square root in order to decrease their dispersion, and subsequently analyzed by deviation analysis. During the observation time, the total of ticks was 1.434: 55.2% corresponding to the anterior region and 44% to the posterior region. It was also noticed a significant difference - 5% - in June and April, occuring the higher parasitic incidence, regarding to September, with a lower incidence. On the right and left sides and median region of the animals body, the variation was: 27.7%, 30.1% and 42.2%, respectively. The counting was higher in June; however, from August to September have showed lower incidences. On mares the distribution was: 59.5% on the anterior region and 40.5% on the posterior region: 32.9% on the right side, 28.1% on the left side and 39% on the median region. It was noticed significative difference among the countings averages on the three last regions in June (with higher incidence) and averages December, May, September, January and February averages (with lower incidences, respectively).