Introduction: A feedlot is an intensive farming system for finishing livestock. Bovine respiratory disease (BRD) is a cause of morbidity and mortality in beef cattle, especially in feedlots. Methodology: This study investigated the morbidity and mortality of BRD in a beef cattle feedlot in southeastern Brazil using: clinical diagnoses, therapy, morbidity, and mortality. Pulmonary fragments were collected from five steers, on feed from 3-32 days, with lesions of pneumonia for identification of BRD infectious agents PCR. Results: 188,862 steers were on feed and morbidity was 7.05% (13,315/188,862), mortality 0.64% (1,214/188,862). The causes of morbidity were: BRD (6.13%), lameness (0.29%), trauma (0.21%), clostridiosis (0.13%) and polioencephalomalacia, PEM (0.12%). The causes of mortality were: BRD (0.21%), trauma (0.17%), and clostridiosis (0.13%). When all sick cattle were considered (n=13,315), BRD (86.9%) was the principal cause of morbidity, followed by lameness (4.13%), trauma (3.05%), and clostridiosis (1.82%). The cost of BRD-associated cattle mortality and morbidity was estimated at $14,334.00/10,000 and $16,315.40/10,000 respectively. It was projected that the economic effects due to BRD-associated morbidity in Brazil were $6.31 million/annum, while losses due to mortality were $5.54 million, resulting in an annual loss of $11.85 million. Coinfections in cattle with pneumonia due to Mannheimia haemolytica and Pasteurella multocida were identified in 4/5 steers tested. Conclusions: This is the first longitudinal study that investigated the incidence of BRD in feedlot cattle from Brazil, and the results herein described indicate that BRD contributed significantly to the development of mortality and morbidity of cattle on feed.

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.

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Teat papillomatosis affects dairy cows worldwide. Milking can become difficult due to teat warts, and maintaining affected cows in the herds may diminish economic profit in the dairy industry. Currently, 13 bovine papillomavirus (BPV) types have been fully characterized, and numerous putative BPV types have been identified through partial L1 gene PCR. In order to identify the viral types present in warts on the udders of dairy cows, 40 teat lesions from 24 cows from 13 cattle farms in three States of Brazil were evaluated by PV L1 gene PCR. The warts that were evaluated contained sequences from BPVs 6-10, the putative BPV types BAPV9 and BAPV4, and two unreported putative papillomavirus (PV) types, named BPV/BR-UEL6 and BPV/BR-UEL7. In addition, mixed infections and coinfections were identified, since more than one lesion was observed on the udders of 13 cows. Phylogenetic analysis showed that BPV/BR-UEL6 is closely related to BPVs belonging to the genus Xipapillomavirus, while BPV/BR-UEL7 clustered with the previously reported strains Cervus timorensis and Pudu puda PVs, which represent a putative new PV type, and it was only distantly related to xi-, epsilon-, delta- and dyoxi-PVs. These results provide information that will assist in the understanding of the association of BPVs 6, 7, 8, 9, and 10, as well as putative BPV types BAPV4 and BAPV9, with mammary papillomatosis. This is the first characterization of putative novel PV types BPV/BR-UEL6 and BPV/BR-UEL7 in teat warts of dairy cows, highlighting the high genetic diversity of BPVs associated with teat papillomatosis.

The bovine respiratory disease (BRD) complex is a multietiological and multifactorial disease associated with a wide range of viral and bacterial pathogens. This study evaluated the contribution of specific infectious disease agents in the development of BRD in cattle from Brazil and determined if a virus within the malignant catarrhal fever virus (MCFV) group and Mycoplasma bovis, acting individually or in conjunction, can be associated with the development of BRD. Formalin-fixed paraffin-embedded pulmonary sections were used in immunohistochemical assays to determine the intralesional presence of six antigens associated with BRD: bovine alphaherpesvirus 1 (BoHV-1), bovine parainfluenza virus 3 (BPIV-3), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), MCFV, and M. bovis. Pneumonia was diagnosed in 82.7% (120/145) of all cattle evaluated. Interstitial pneumonia (60%, 72/120) and suppurative bronchopneumonia (25.8%, 31/120) were the most frequent patterns of pneumonia identified. Intralesional antigens of MCFV (53.3%, 64/120) were the most frequently associated with BRD, followed by M. bovis (47.5%, 57/120), BVDV (42.5%, 51/120), BoHV-1 (28.3%, 34/120), BRSV (24.2%, 29/120), and BPIV-3 (8.3%, 10/120). Additionally, antigens of BVDV, MCFV, and M. bovis were the most frequently identified agents associated with singular and concomitant infections. The MCFV identified during this study is more likely to be ovine gammaherpesvirus 2 (OvHV-2), since OvHV-2 is the only MCFV identified within the geographical region of this study. Interstitial pneumonia with proliferative vascular lesions may be a useful histologic feature to differentiate MCFV-induced pneumonia from other viral pneumonias of cattle. These results demonstrate that MCFV and M. bovis, in single or mixed infections, can produce pneumonia in cattle and should therefore be considered as primary agents in the development of BRD.

ABSTRACT. Bovine coronavirus (BCoV) is a pathogen related to enteric and respiratory diseases in cattle worldwide. Enteric (BECoV) strains of BCoV are predominant in South America, and genetic investigations have been conducted to identify its relationship with isolates of respiratory origin (BRCoV). In this study, we used a BRCoV strain (BR-UEL11) derived from an outbreak of respiratory disease in feedlot cattle in southern Brazil, and compared the partial sequence of the polymorphic region of Spike (which was detected and sequenced by two distinct reverse transcription-polymerase chain reactions) with those of other BCoV strains. The phylogenetic relationship of BR-UEL11 with Brazilian BCoV, which is associated with calf diarrhea and winter dysentery (enteric, BECoV; respiratory, BRCoV), and classical reference prototypes was analyzed. The analysis showed that the BRCoV strains from Brazil clustered with a clade that was distinct from most isolates associated with calf diarrhea (BECoV) and ancestral prototype strains such as Mebus, Nebraska, and LYVB. Furthermore, the BRCoV strains from Brazil clustered with a clade that contained recent strains associated with winter dysentery, showing 98-99% nucleotide identity with those strains. These results suggested that the Brazilian BCoV evolved from being solely enteric to a dual enteric and respiratory tropic virus.

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This study presents the pathological, immunohistochemical, and molecular findings associated with the extra-intestinal detection of canine kobuvirus (CaKV) in a 5-month-old Chihuahua puppy, that had a clinical history of bloody-tinged feces. Principal pathological findings were interstitial pneumonia, necrotizing bronchitis, and parvovirus-induced enteritis. Molecular diagnostic methods identified CaKV within the cerebellum, cerebrum, lung, tonsil, and liver. CaKV and rotavirus were not identified within the feces and intestine. Immunohistochemistry (IHC) assays detected antigens of CDV and CAdV-1 in the lungs. These results confirmed the extra-intestinal detection of CaKV in this puppy and represent the first extra-intestinal detection of CaKV in a dog.