Hepatite infecciosa e parvovirose cardíaca em cães.

Abstract

Infectious diseases represent the major cause of death or reason for euthanasia of dogs in Brazil. While some diseases are often diagnosed, others are only occasionally and are potentially fatal, such as canine infectious hepatitis and cardiac form of parvovirosis. This dissertation, presented to the Graduate Program of Veterinary Medicine of the Federal University of Campina Grande, is divided into two chapters, each chapter being represented by one scientific article. The first article, submitted to the journal Arquivo Brasileiro de Medicina Veterinária e Zootecnia, describes the main epidemiological, clinical and anatomopathological aspects of cases of infectious canine hepatitis diagnosed in the Laboratory of Animal Pathology during the period from January 2003 to December 2016. Of the 1,640 necropsied dogs, 15 were diagnosed as infectious canine hepatitis (0.91%). Of the dogs affected nine were males and six females. The ages ranged from 45 days to seven years, being most of them young. Ten animals were mixed breed, four were Poodles and one Rottweiler. Most of the dogs do not received any vaccine protocol. The dogs came from the municipalities of Patos, São Mamede and Teixeira, from the backland of the Paraiba, Northeast of Brazil. Most of the dogs presented clinical course varying from hyperacute to acute. The main clinical signs were seizure, apathy and hyporexia. At necropsy, the major alterations were observed in the liver, which was pale to orange and with irregular reddish areas on the capsular surface, besides accentuation of the lobular pattern and edema in the wall of the gallbladder. Hemorrhages were observed in several organs. In the histopathology of the liver there was mainly centrilobular necrosis, associated with intranuclear viral inclusion bodies in hepatocytes, hemorrhage and discrete mixed inflammatory infiltrate. Viral inclusions bodies could be visualized also in the vascular endothelium of the encephalon and in the glomerular capillaries, besides spleen and lymph nodes. The diagnosis was established based on the characteristic histopathological lesions and was confirmed by immunohistochemistry. The second article, submitted to the journal Pesquisa Veterinaria Brasileira, describes epidemiological, clinical, pathological and immunohistochemical aspects of an outbreak of cardiac parvovirosis in puppies. The outbreak occurred in a kennel located in Parnamirim, Rio Grande do Norte, Northeastern of Brazil. In a litter of nine pups, one was stillbirth and six died between 35-57 days of age after cardiopulmonary clinical signs with evolution of 10 minutes to three days. Of the six puppies that died, two were sent for necropsy. On gross examination, both animals had discreet pericardial effusion, markedly distended heart, diffuse pallor in epicardial and myocardial surfaces and dilation of the left ventricular cavity. In the lungs were observed multifocal reddish areas in the pleural surface. The livers were diffusely increased in size, with lobular standard accentuation and pale areas interspersed with dark areas. Microscopically was observed linfohistiocítica myocarditis, necrotizing, associated with interstitial fibrosis and basophilic intranuclear viral inclusions corpuscles in cardiomyocytes. In the lungs there were edema and interstitial pneumonia and in the liver was noted centrilobular to mediozonal degeneration and necrosis associated with congestion and hemorrhage. The diagnosis was confirmed by immunohistochemistry. With the accomplishment of these studies it can be considered that infectious canine hepatitis and the cardiac form of the canine parvovirosis occur occasionally in the diagnostic routine of the Laboratory of Animal Pathology of the Veterinary Hospital of the UFCG and still represent important causes of death in dogs.