HISTOPATHOLOGICAL ASPECTS OF DIGITAL DERMATITES IN DAIRY COWS

Abstract

In order to evaluate the histopathologic alterations caused by digital dermatitis, 60 cases of the disease and 240 dairy cows in the district of Brumadinho- Minas Gerais, Brazil, were examined and observed. The lesions were macroscopically classified as hiperplastic (grade 1), ulcerative (grade 2) and proliferative (grade 3), which the grade 1 lesions took an average of 28 days to evolutes for a grade 2 lesion and these took and average of 45 days to become a grade 3 lesion. Lesions biopsies were done and samples were collected and send to a laboratory, they were processed, colored by Hematoxilin-Eosin and then they were analyzed by optical microscopy. The major histopathological founds of hiperplastic forms were intense hyperkeratosis and centrocellular vacuolation. In the ulcerative form discontinuous of epiderm was observed, also, stratum corneum erosion, with corneal columns presenting areas of vacuolar degeneration and necrosis, hemorrhages with inflammatory cells were seen. In the proliferative form the epiderm was thickened with pronounced papillary formations passing from stratum spinosum until the corneum. In the papillary dermic zone there was abscedation with inflammatory infiltrates mostly neutrophilic. KEY WORDS: Digital dermatitis, histopathology.