Abstract Tuberculosis (TB) is a chronic disease caused by bacteria belonging to the Mycobacterium tuberculosis complex (MtbC). This disease rarely affects dogs. Canine infections are usually caused by M. tuberculosis. Mycobacterium bovis infections are rare in dogs and associated with consumption of raw milk or contaminated products. Here, we report a Boxer dog who had a M. bovis infection and was admitted to a Brazilian veterinary hospital with a presumptive diagnosis of chronic ehrlichiosis. Despite receiving treatment for chronic ehrlichiosis, it progressed to death. TB was diagnosed during post-mortem examinations using histopathological analysis. Ziehl-Neelsen staining revealed acid-fast bacilli in the kidneys, liver, mesentery, and a mass adhered to the liver. Further, PCR-restriction analysis was performed to identify mycobacteria in the samples. A restriction profile compatible with MtbC was found in the lungs. In addition, PCR-based MtbC typing deletions at different loci of chromosome 9 enabled the identification of M. bovis in the lungs. Therefore, it is very essential to perform differential diagnosis of TB in dogs with non-specific clinical signs and who do not respond to treatment, particularly those who had been in contact with TB-infected cattle or owners. Further, we highlight the use of molecular methods for the identification of bacilli, improving the diagnosis and aiding epidemiological studies.

O objetivo do presente trabalho foi determinar a frequência de propriedades positivas (focos) e de animais positivos para a tuberculose bovina no Estado da Paraíba. Foram utilizados dados da Agência de Defesa Agropecuária do Estado, coletados de suas 23 microrregiões, durante o período de janeiro de 2008 a julho de 2009. Durante esse período, foram examinadas 10.963 propriedades e 54.472 bovinos foram submetidos ao teste de tuberculinização. Para o diagnóstico foi utilizada, como prova de triagem, a tuberculinização cervical simples para gado de leite e a tuberculinização na prega caudal para gado de corte; como prova confirmatória foi utilizada a tuberculinização cervical comparativa. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. Das propriedades investigadas, 62 (0,57%) apresentaram pelo menos um animal positivo e dos animais analisados, 136 (0,25%) foram positivos. Houve diferença significativa (p<0,001) na proporção de fêmeas (0,32%) e machos (0,04%) positivos. A despeito da baixa freqüência de focos de brucelose e de animais soropositivos, é necessária a condução de medidas que incluem a conscientização dos produtores, fiscalização nas barreiras sanitárias e levantamentos periódicos da situação epidemiológica desta doença, principalmente nas microrregiões com maior frequência da infecção, com o objetivo de evitar, ou pelo menos minimizar, a disseminação do agente.

The aim of this study was to determine the frequency of positive herds (foci) and positive animals for bovine tuberculosis in the state of Paraíba, Northeast region of Brazil. Data from the Agency of Agricultural Protection in the state, collected from its 23 microregions, during the January 2008 to July 2009 period, were used. During this period, 10,963 herds were examined and 54,472 cattle were submitted to the tuberculin test. For diagnosis the cervical and caudal-fold tuberculin tests were used as screening tests in dairy and beef cattle, respectively; as confirmatory test, comparative cervical test was used. A herd was considered focus when presented at least one positive animal. Of the herds investigated, 62 (0.57%) had at least one positive animal, and of the animals examined, 136 (0.25%) were positive. There was significant difference (p<0.001) in the proportion of positivity for females (0.32%) and males (0.04%). Despite low frequency of foci of brucellosis and seropositive animals, it is necessary to conduct measures including awareness of producers, surveillance in sanitary barriers and periodic surveys of epidemiological situation of this disease especially in the regions with highest frequency of infection, aiming to avoid, or at least minimize, the spread of the agent.