Fase parasitária e alteracoes clínicas em bovinos infestados experimentalmente com larvas de dermatobia hominis / Parasitic phase and clinical changes in cattle experimentally infested with larvae of dermatobia hominis

RESUMO

The duration of the parasitic phase of Dermatobia hominis and the clinical changes of artificially infested cattle with this parasite larvae have been studied. A group consisting of six artificially infested animals with 60 newly hatched D. hominis larvae (L) per animal, as well as a control group of six animals, were used. The two groups of animals were weekly accompanied, until the 63nd day after the infestation (DAI), being evaluated the values of the rectal temperature and heart and respiratory rates. For occasion of the 7th DAI, it was already possible to observe the parasitic nodules in the subcutaneous tissues of the infested animals. With the larval development, these nodules reached about 2 to 3 cm of diameter, and the duration of the parasitic phase ranged from 33 to 41 days. In relation to the clinical parameters studied (rectal temperature, heart and respiratory rates), there were no significant differences (P>0,05) between the averages of infested group and control group, during the study period. The variations of the rectal temperature values showed, during the whole experimental period, unside of the normality limits. It was also verified in the infested and control animals a significant Pearson coefficient (r=0,89 <0,01) between the values of the respiratory rate and room temperature