We examined the pathogens, morphologic patterns, and risk factors associated with bovine respiratory disease (BRD) in 136 recently weaned cattle ("weanlings"), 6-12 mo of age, that were submitted for postmortem examination to regional veterinary laboratories in Ireland. A standardized sampling protocol included routine microbiologic investigations as well as polymerase chain reaction and immunohistochemistry. Lungs with histologic lesions were categorized into 1 of 5 morphologic patterns of pneumonia. Fibrinosuppurative bronchopneumonia (49%) and interstitial pneumonia (48%) were the morphologic patterns recorded most frequently. The various morphologic patterns of pulmonary lesions suggest the involvement of variable combinations of initiating and compounding infectious agents that hindered any simple classification of the etiopathogenesis of the pneumonias. Dual infections were detected in 58% of lungs, with Mannheimia haemolytica and Histophilus somni most frequently recorded in concert. M. haemolytica (43%) was the most frequently detected respiratory pathogen; H. somni was also shown to be frequently implicated in pneumonia in this age group of cattle. Bovine parainfluenza virus 3 (BPIV-3) and Bovine respiratory syncytial virus (16% each) were the viral agents detected most frequently. Potential respiratory pathogens (particularly Pasteurella multocida, BPIV-3, and H. somni) were frequently detected (64%) in lungs that had neither gross nor histologic pulmonary lesions, raising questions regarding their role in the pathogenesis of BRD. The breadth of respiratory pathogens detected in bovine lungs by various detection methods highlights the diagnostic value of parallel analyses in respiratory disease postmortem investigation.

A retrospective analysis was conducted to investigate the prevalence and seasonality of bovine viral diarrhoea virus (BVDV), bovine coronavirus (BoCV), bovine herpesvirus-1 (BoHV-1), bovine respiratory syncytical virus (BRSV) and parainfluenza virus-3 (PI3V) in calves (aged three months and below) in Ireland. Results from real-time PCR testing, including cycle threshold values, conducted on nasal swabs (single or pooled) submitted from 1364 respiratory disease outbreaks between January 1, 2008 and December 31, 2012 were included in this study. One or more viruses were detected in 34.6 per cent of submissions, with BoCV detected most frequently (22.9 per cent), followed by BRSV (11.6 per cent), PI3 V (7.0 per cent), BoHV-1 (6.1 per cent) and BVDV (5.0 per cent). The detection rate of all viruses was higher when pooled multiple swabs were submitted from outbreaks rather than single swabs, with these differences being significant for all except BVDV. Two or more viruses were detected in 39.4 per cent of positive submissions, with BoCV and BRSV most commonly present as one of the two partners in detection. With the exception of BVDV, which was detected all year round, the others showed a clear seasonal pattern, being most commonly detected in winter and spring.

The voluntary phase of an industry-led national Bovine Viral Diarrhoea (BVD) eradication programme began in Ireland on January 1, 2012 with the goal of progressing to a compulsory programme in 2013. The development and implementation of the programme in 2012 was informed by a review of current and prior eradication programmes elsewhere in Europe and extensive stakeholder consultation. The programme was based on tissue tag testing of newborn calves in participating herds, with the status of the mothers of calves with positive or inconclusive results requiring clarification. Participating herd owners were required to comply with a series of guidelines, including not selling cattle suspected of being persistently infected. For herds compliant with the guidelines, the results from 2012 counted as one of three years of tag testing anticipated in the compulsory phase of the programme. Testing was carried out in laboratories designated for this purpose by the cross-industry BVD Implementation Group that oversees the programme. Results were reported to a central database managed by the Irish Cattle Breeding Federation, and the majority of results were reported to farmers' mobile telephones by SMS message. A detailed review of the programme was conducted, encompassing the period between January 1, 2012 and July 15, 2012, based on results from approximately 500,000 calves. This paper describes the establishment and structure of the programme, and the outcomes of the review, including findings at herd and animal level.