Neoplasias diagnosticadas em caninos na região sul do Rio Grande do Sul entre 2000-2017: correlação histoquímica, imuno-histoquímica e variações genéticas

Abstract

The increase in the incidence of tumors in domestic animals is a growing concern in veterinary practice and an important cause of death in several species, mainly dogs and cats. Among these neoplasms, breast cancer and round cell tumors such as lymphoma and transmissible venereal tumor (TVT) are frequently diagnosed in the area of influence of the Regional Diagnostic Laboratory of the Faculty of Veterinary Medicine of the Federal University of Pelotas (LRD / UFPel). Therefore, three scientific papers were included in this thesis. In the first, a retrospective study of canine lymphomas diagnosed in the LRD / UFPel between 2000 and 2017 was carried out to determine their epidemiology and anatomical distribution, and to evaluate the histopathological and immunohistochemical aspects of these lymphomas, according to the modified Kiel classification. Lymphoma was observed in 77 dogs. The multicentric form was the most prevalent, representing 71.4% (55/77) of the diagnoses. In 40 cases immunophenotyping was performed, and B-cell lymphomas accounted for 62.5% of the diagnoses (25/40), while T-cell lymphomas corresponded to 37.5% of the diagnoses (15/40). The degree of malignancy according to the modified Kiel classification was low in 35% of lymphomas (14/40) and high in 65% of cases (26/40). The multicentric form was more frequent in the region of influence of the LRD / UFPel. In a second paper, a molecular study was carried out to identify mutations in exons 7 and 8 in the TP53 gene in canine mammary tumors. Twenty mammary tumors of mixed breed female dogs were analyzed.The sequencing of the other exons and intron regions as well as the increase in the number of dogs analyzed may reveal alterations not detected here, demonstrating the importance of expanding the present study. IHQ is an important tool for differentiating canine TVT from other round cell tumors.