The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum
appeared with a prevalence of 70% in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis
. Histological findings in the ceca were represented by the presence of H. gallinarum
worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils) leucocyte infiltrations. The prevalence of the protozoan H. meleagridis
associated to H. gallinarum
was of 2.5% and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai
; the parasite was prevalent in 20% of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.