Culled sheep, 44 in total, from two sheep flocks with losses due to paratuberculosis were studied. In these animals, pathological studies in samples from the ileocecal valve and ileum (HE and ZN stains) were carried out. Paratuberculous lesions were observed in 26 animals. The lesions were classified as follows: Type I (Focal lesions, with the granulomas located only in the Peyer's patches); Type II (Granulomatous lesions mainly located in Peyer's patches and with invasion of related mucosa); Type III (Diffuse granulomatous lesion involving mucosa nonrelated with Peyer's patches). A total of 14 animals had Type I lesion; 4 had Type II and 8 presented Type III lesion. AGID test were performed on all animals of the flocks, including the culled sheep; 3% of them were serologically positive. Among the culled sheep, 18% were serologically positive (7 out of the 39 tested), 5 of them showed lesions Type III, and 2 lesions Type II. The sensitivity of the AGID test was 27% with 100% of specificity. The low percentage of infected sheep detected by AGID, and the high prevalence of the infection in the flocks with the presence of seronegative sheep with Type I lesion must be addressed.