Résumé
The avian malaria caused by Plasmodium juxtanucleare in Gallus gallus, is a tipical plasmodiose from Brazilian gallinaceous. This disease can causes morbidy and mortality in its vertebrate hosts. This work was conducted at Boa Vista farm, Municipality of Santa Bárbara do Tugúrio, Minas Gerais, Brazil and the ours objectives were to evaluate the hight prevalence found in previous studies and to accompany the variation of the erytrocytic forms during one year. The bloods smears, dyed with Giemsa were examined in microscopy immersion. Twenty five half-breed fowls were accompany duting one year, monthly (from November/00 to May/01) and biweekly (from June/01 to October/01). The erytrocytic forms were registered and quantified by the observation of 100 microscopic fields. Was verified a prevalence of 100 por ciento by P. juxtanuclerare, but there wasn't statistics correlation between the increase of the erytrocytic forms during the year. The trophozoites were the more abundant form found in this studie.