Observations on single brucellosis reactors in large herds

Specimens were collected during 3 years from herds that contained single reactors to the complement fixation test for brucellosis, from large herds in north Queensland. Twenty-four such reactors were destroyed for culture, and Brucella abortus was isolated on 3 occasions. The existence of such low levels of Br. abortus infection in large herds should not be overlooked in the eradication campaign. Explanations were found for 17 of the single reactors, and included introduction of cattle to the herd, exposure to adjoining infected herds or vaccination with Strain 19

Observations on single brucellosis reactors in large herds

Specimens were collected during 3 years from herds that contained single reactors to the complement fixation test for brucellosis, from large herds in north Queensland. Twenty-four such reactors were destroyed for culture, and Brucella abortus was isolated on 3 occasions. The existence of such low levels of Br. abortus infection in large herds should not be overlooked in the eradication campaign. Explanations were found for 17 of the single reactors, and included introduction of cattle to the herd, exposure to adjoining infected herds or vaccination with Strain 19

Clinical and pathological observations on goats experimentally infected with Pseudomonas pseudomallei

The effects in goats of the subcutaneous injection of varying doses of Pseudomonas pseudomallei (90 to 500000 bacilli) suspended in normal saline are described. High doses ( more than or equal to 500 bacilli) caused acute, fatal infections. Lower doses (90 to 225 bacilli) caused acute or chronic disease when infection became established. However, 11 of 18 goats injected with the lower doses of bacilli showed no sign of infection on clinical or bacteriological examination. Response to antibiotic therapy with long acting tetracycline and chloramphenicol was minimum. Goats surviving the initial phase of infection tended to overcome the disease with a corresponding increase in the number of abscesses that were sterile at PM. In infected goats, clinical signs included undulating fever, wasting, anorexia, paresis of the hind legs, severe mastitis and abortion. PM examination revealed abscesses, predominantly in the spleen, lungs, subcutaneous injection site and its draining lymph node

Clinical and pathological observations on goats experimentally infected with Pseudomonas pseudomallei

The effects in goats of the subcutaneous injection of varying doses of Pseudomonas pseudomallei (90 to 500000 bacilli) suspended in normal saline are described. High doses ( more than or equal to 500 bacilli) caused acute, fatal infections. Lower doses (90 to 225 bacilli) caused acute or chronic disease when infection became established. However, 11 of 18 goats injected with the lower doses of bacilli showed no sign of infection on clinical or bacteriological examination. Response to antibiotic therapy with long acting tetracycline and chloramphenicol was minimum. Goats surviving the initial phase of infection tended to overcome the disease with a corresponding increase in the number of abscesses that were sterile at PM. In infected goats, clinical signs included undulating fever, wasting, anorexia, paresis of the hind legs, severe mastitis and abortion. PM examination revealed abscesses, predominantly in the spleen, lungs, subcutaneous injection site and its draining lymph node

Confirmação de infecção por Brucella abortus em um rebanho bovino certificado livre em Minas Gerais: relato de caso

Relata-se a ocorrência de um surto de brucelose em um rebanho de aproximadamente 1000 animais, livre da doença há 18 anos, certificado pelo Ministério da Agricultura, Pecuária e Abastecimento desde 2006. Dois animais reagiram aos testes sorológicos de diagnóstico por ocasião dos procedimentos de recertificação em 2008. Após o sacrifício deles, Brucella abortus, biovariedade 1, amostra não vacinal, foi isolada e identificada por meio de provas bioquímicas e de biologia molecular (PCR AMOS). A origem do agente no rebanho é de difícil determinação. No entanto, a adoção de procedimentos preconizados pelo Programa Nacional de Controle e Erradicação da Brucelose permitiu evitar a disseminação da enfermidade. Ocorrências como essas, em que rebanhos livres foram infectados após anos sem a ocorrência de brucelose, nunca haviam sido relatadas no Brasil

Polioencefalomalacia em bovinos nos estados de Mato Grosso do Sul e São Paulo Polioencephalomalacia in cattle in the states of Mato Grosso do Sul and São Paulo

Trinta focos de polioencefalomalacia (PEM) foram diagnosticados no período de agosto de 1993 a outubro de 1997. Vinte e nove focos ocorreram no estado de Mato Grosso do Sul (MS) e um no estado de São Paulo (SP). Foram afetados bovinos de 4 a 84 meses de idade. A morbidade dos rebanhos afetados variou de 0,02% a 14,28% e a letalidade de 42,5% a 100%. A doença não apresentou uma sazonalidade e ocorreu em vários municípios do MS. Em todos os focos estudados os animais afetados eram criados em regimes de criação extensiva, com exceção de um foco. Os sinais clínicos observados foram exclusivamente nervosos e a evolução dos casos variou de 12 horas a 4 dias. A maioria dos animais tratados com tiamina e dexametasona recuperou-se. Histologicamente, as lesões consistiam de necrose laminar do córtex cerebral. Adicionalmente em 2 casos observaram-se hemorragias submeningeanas e corticais, e em 9 casos presença de infiltrado de eosinófilos. A dosagem de sódio no líquor apresentou-se elevada em um caso. A etiologia da PEM não está esclarecida, porém em alguns casos a intoxicação por cloreto de sódio/privação de água pode estar envolvida na etiologia da enfermidade. A PEM representa 4,78% dos casos de enfermidades de bovinos diagnosticadas no Laboratório de Anatomia Patológica da UFMS. Com bases nos resultados, verifica-se a importância da enfermidade no diagnóstico diferencial de outras doenças com quadro clínico neurológico no MS, principalmente a raiva, a meningoencefalite por herpesvírus bovino tipo 5 (HVB-5) e o botulismo.<br>Thirty outbreaks of polioencephalomalacia (PEM) were diagnosed from August 1993 to October 1997. Twenty nine occurred in the state of Mato Grosso do Sul and one in São Paulo. The disease affected cattle from 4 months to 7 years of age. Morbidity rates ranged from 0.02% to 14.28% and case fatalities from 42.5 % to 100%. The disease was not seasonal. All outbreaks occurred in cattle grazing Brachiaria spp, except one affecting feedlot cattle. Only neurologic signs were observed, and the course of the disease varied from 12 hours to 4 days in untreated cattle. Most animals treated with thiamine and dexamethazone recovered. Moderate cerebral edema was observed at necropsy. Cell changes were characterized by laminar necrosis and gitter cells. In two cases moderate cortical and submeningeal hemorrhages were observed. Nine cases had perivascular and submeningeal infiltrations by eosinophils. Sodium ion concentration of the cerebrospinal fluid was elevated in one case. The cause of PEM in the region was not determined, but the results suggest that in some cases sodium chloride intoxication/water deprivation could play a role in the etiology of the disease. PEM represents 4.78% of cattle disease diagnosed at the Pathology Laboratory of the Federal University of Mato Grosso do Sul