A study was designed to determine the seroprevalence of N. caninum in dairy cattle in the area of Grande Sama Sama -Inclan District , Province and Department of Tacna. Blood samples from 115 dairy cattle distributed by age ( 2 to 4.5 , <4.5 to 7 and < 7-10 years) and place of origin ( Arequipa. Ite , Sama and Yarada ). By immunofluorescence test was determined seroprevalence N. caninum , which turned out to be moderate with a value of 28.70 ± 8.27 , considering the age of the animals was observed that animals of< 7-lO years had the highest values of seroprevalence (44.44 ± 32 , 46 ) , then the animals of 2 to 4.5 years ( 27.87 ± 11.25 ) , and finally the animals of < 4.5 to 7 years ( 26.67 ± 12.92 ) , respectively. On the other hand , the seroprevalence of the parasite into consideration the place of origin was 30.00 ± 16.40 for animals from Arequipa, 50.00 ± 40. 01 for...