In trematodes contaminated farms there is an increase in the culling of young animals and cows at the beginning of lactation with signs of hepatitis, jaundice, digestive disorders and a decrease in productivity against the background of general exhaustion. The aim of the study is to study the age and seasonal dynamics of infection with trematodes in cattle. The study of the epizootology of dicrocoeliasis of cattle was carried out at different times of the year according to coprological surveys of 278 heads. Intravital diagnostics was carried out by examining fecal samples by the flotation method and the results of helminthological dissections of the liver and gallbladder in 55 animals in July, October, December and April, taking into account the data of the state veterinary and sanitary examination laboratories of the Altai region. The extensiveness of invasion increased with the age of the animals and up to a year was 2.9% when finding 11.2 ± 1.5 eggs of dicrocoelium. The increase in extensity and intensity of invasion is associated with the accumulation of helminths in the body of animals with annual infection in the grazing period and a high lifespan of dicrocoelium. According to the data of parasitological studies, it has been established that cattle are infected with dicrocoelium during the year. The extent of invasion varied from 2.9 to 10.8 %.