Caudal vena cava thrombosis in cattle in Southern Brazil: clinical and pathological aspects of 30 cases

Hemoptysis associated with respiratory disorders are some findings of caudal vena cava thrombosis (CVCT) in cattle. Nevertheless, CVCT may be accompanied by a broad spectrum of clinical signs and gross lesions. This study reported the frequency of CVCT in cattle necropsied in Southern Brazil and described its clinical signs, as well as pathological findings. From a total of 1,976 postmortem examination reports in cattle in Southern Brazil, there were 30 cases (1.5%) of CVCT. In the clinical evaluation, the main clinical course was chronic (13/30), followed by peracute (7/30), acute (4/30), and subacute (5/30). Hemoptysis (17/30), dyspnea (8/30), and anorexia or hyporexia (7/30) were the most reported clinical signs. Septic thrombophlebitis of the caudal vena cava (24/30), hepatic abscesses (24/30), pulmonary hemorrhage (23/30), and embolic pneumonia (19/30) were the main lesions observed at the necropsy. We concluded that CVCT is a relevant cause of death in bovines from Santa Catarina state, mainly in adult dairy cows. The disease is characterized by a wide range of clinical signs and lesions, requiring attention from veterinarians for the correct diagnosis. Furthermore, the association between the clinical history, clinical signs, and lesions is essential for the diagnosis of CVCT in cattle. RESUMO: Hemoptise associada a sinais respiratórios são achados típicos de tromboembolismo da veia cava caudal (TVCC) em bovinos. Todavia, o TVCC pode estar acompanhado de um amplo espectro de sinais clínicos e lesões macroscópicas. Esse estudo tem por objetivo relatar a frequência do diagnóstico de TVCC em bovinos necropsiados no sul do Brasil e descrever os sinais clínicos, assim como achados patológicos dessa condição. De um total de 1.976 exames post-mortem realizados em bovinos no Sul do Brasil, 30 casos de TVCC foram diagnosticados (1,5%). No exame clínico, o principal curso clínico observado foi crônico (13/30), seguido do hiperagudo (7/30), agudo (4/30) e subagudo (5/30), em um caso o histórico clínico não foi fornecido. Hemoptise (17/30), dispneia (8/30) e anorexia ou hiporexia (7/30) foram os sinais clínicos mais comumente relatados. Tromboflebite séptica da veia cava caudal (24/30), abscessos hepáticos (24/30), hemorragia pulmonar (23/30) e pneumonia embólica (19/30) foram as principais lesões observadas na necropsia. Com esse trabalho conclui-se que TVCC é uma causa relevante de morte em bovinos no estado de Santa Catarina, principalmente em vacas leiteira