Incidência e distribuição de amblyomma cajennense em regiões corporais de eqüinos das raças mangalarga marchador e bretão postier, naturalmente infestados / Amblyomma cajennense: adults distribution and incidence on the body of naturally infested mangalarga marchador and bretao postier horses

RESUMEN

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 per cent corresponding to the anterior region and 44 per cent to the posterior region. It was also noticed a significant difference - 5 per cent - 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 por ciento, 30.1per cent and 42.2 per cent, respectively. The counting was higher in June; however, from August to September have showed lower incidences. On mares the distribution was 59.5 per cent on the anterior region and 40.5 per cent on the posterior region 32.9 per cent on the right side, 28.1 per cent on the left side and 39 per cent 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).