Aspectos clínicos, epidemiológicos e morfológicos de tromboflebite de veia cava caudal em bovinos

Abstract

Thrombophlebitis of caudal vena cava is a serious disorder of cattle, usually fatal, that causes economic losses to farmers and the Brazilian livestock. The disease is often associated with diets rich in grain introduced without adaptation, resulting in ruminal acidosis. This, in turn, favors liver abscesses formation, which increases in volume and, upon reaching the wall of the caudal vena cava or vena hepatica, ruptures into them, causing septic embolization and death. Better knowledge of the disease's epidemiological and morphological aspects of increases the likelihood of a correct diagnosis of vena cava thrombophlebitis. For this purpose, cases of the disease diagnosed in the Veterinary Pathology Sector of UFLA from 2004 to 2020 were studied. Clinical, epidemiological, gross, and histologic aspects of sixteen cases of caudal vena cava thrombophlebitis in cattle were evaluated. The disease was diagnosed in dairy cattle, with a major occurrence in females and an age average of two years and eight months. Analyzing the occurrence throughout the year, more cases occurred in the dry season, which extends from April to September in the Southeast Region of Brazil. The studied cases were from 12 farms in the Lavras Region and all of them used food supplementation with grain concentrate; however, in one case the disease was associated with the use of corn straw. In four cases, there were observed elimination of varying amounts of blood through the upper respiratory tract and mouth. At necropsy, liver abscesses were seen in eleven bovines, and large thrombi occluding the vena cava were seen in ten. The histochemical evaluation highlighted bacteria in the lesions. The disease needs to be most known to be better diagnosed and prevented, which motivated this study.