We investigated the occurrence of infectious pathogens during an outbreak of bovine respiratory disease (BRD) in a beef cattle feedlot in southern Brazil that has a high risk of developing BRD. Nasopharyngeal swabs were randomly collected from steers ( n = 23) and assessed for the presence of infectious agents of BRD by PCR and/or RT-PCR assays. These included: Histophilus somni, Mannheimia haemolytica, Pasteurella multocida, Mycoplasma bovis, bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCoV), bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoHV-1), and bovine parainfluenza virus 3 (BPIV-3). Pulmonary sections of one steer that died with clinical BRD were submitted for pathology and molecular testing. The frequencies of the pathogens identified from the nasopharyngeal swabs were: H. somni 39% (9 of 23), BRSV 35% (8 of 23), BCoV 22% (5 of 23), and M. haemolytica 13% (3 of 23). PCR or RT-PCR assays did not identify P. multocida, M. bovis, BoHV-1, BVDV, or BPIV-3 from the nasopharyngeal swabs. Single and concomitant associations of infectious agents of BRD were identified. Fibrinous bronchopneumonia was diagnosed in one steer that died; samples were positive for H. somni and M. haemolytica by PCR. H. somni, BRSV, and BCoV are important disease pathogens of BRD in feedlot cattle in Brazil, but H. somni and BCoV are probably under-reported.

This study investigated the participation of infectious agents in spontaneous abortions and reproductive problems at eight dairy cattle herds from three geographical regions of Brazil. Fourteen aborted fetuses and the organ sections of one cow with history of repeated abortions were received for pathological evaluations and molecular diagnostics. PCR/RT-PCR assays targeted specific genes of abortifacient agents of cattle: bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHV-1), Listeria monocytogenes, Neospora caninum, Leptospira spp., Brucella abortus, and Histophilus somni. Six fetuses were adequate for pathological investigations; one of these did not demonstrate remarkable pathological alterations. Significant histopathological findings included vasculitis, hemorrhage, and fibrinous thrombosis of the cerebrum (n = 4); necrotizing myocarditis (n = 3); and hemorrhagic enteritis (n = 3). The placenta and uterus of the cow as well as the kidney, pancreas, and liver of her aborted fetus contained H. somni DNA and demonstrated histopathological evidence of histophilosis. All fetuses contained H. somni DNA in multiple organs. Coinfections of H. somni with B. abortus (n = 2), N. caninum (n = 2), BVDV (n = 1), and BoHV-1 (n = 1) were identified; two fetuses demonstrated three pathogens. These findings suggest that H. somni was associated with the spontaneous abortions and reproductive problems of these herds. However, the exact cause of fetal death might not be attributed only to H. somni in all aborted fetuses, since some of these were infected with other abortifacient agents.

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ABSTRACT:The objective of this study was to determine the gamma-glutamyl transferase (GGT) levels and its relationship with diarrhea and passive transfer of immunity in Holstein calves within 24 hours and 30 days of life from Leopolis municipality, the north Parana region. Colostrum is rich in immunoglobulins and vital for immunity to newborn calves, since bovine placenta does not allow the passage of immunoglobulin to the fetus. Calves undergo various challenges that can lead to disease and death in the first month of life, including diarrhea. Diarrhea has a multifactorial etiology, and the passive immunity transferred through ingestion of colostrum is able to protect the calf against many of these etiologic agents. GGT measurements indirectly infer the amount of immunoglobulin ingested by the calf. Higher serum GGT levels (381.72 IU / L) were found at 24 hours, and a significant reduction was observed at 30 days (66.22 IU / L). When the presence or absence of diarrhea was associated with GGT levels above and below 200 IU / L, no statistical significance (P> 0.05) was observed, since 80% of animals with diarrhea had serum GGT levels higher than 200 IU / L. Under the conditions of this study, there was no relationship between the GGT concentration and the occurrence of diarrhea, and no mortality was observed despite some animals presented diarrhea.

Lesões pulmonares de bovinos encontradas na inspeção postmortem em matadouros frigoríficos no estado do Paraná Bovine pulmonary lesions found in post-mortem inspection in slaughterhouse in state Paraná