ANIMALS are regularly tested for bovine TB, with the frequency of testing increasing in areas where the risk of infection is high, writes Iain Steele of Belle Vue Vets.Targeted testing is also used to try and safeguard the movement of animals out of high-risk areas with pre- and post-movement testing carried out. Where outbreaks are identified, holdings are placed under movement restrictions, meaning that animals cannot leave the farm unless direct to slaughter; a further attempt to reduce spread. The removal of infected animals from the population as quickly as possible is also integral to control.

Bovine TB, as a national cattle health priority, has interesting parallels with Covid-19. However, on a more day to day basis, lessons learned during the pandemic would be worth consideration during any pneumonia outbreak on-farm. Like Covid-19, the spread of pneumonia causing pathogens is heightened where stocking density is high and ventilation poor. If pneumonia is a recurrent problem on farm then improvement of ventilation in existing sheds, or investment in new, purpose-built calf housing would be worthwhile. As temperatures drop during winter, a calf’s ability to fight off infection will be diminished as it utilises energy to keep warm. Calf jackets, increased bedding and increased feeding rates should all be used when temperatures drop below the calf’s ‘lower critical temperature’ (10-15°C for calves three weeks old).

When a pneumonia outbreak occurs, isolation of infected animals - including animals with a high temperature yet to exhibit more obvious signs like coughing or nasal discharge - will reduce spread to uninfected calves. Testing of calves with pneumonia is also critical to control, as unlike Covid where one bug is solely responsible for disease, bovine respiratory disease is caused by many pathogens – both viral and bacterial. Determining the causative agent will help tailor control methods in future batches of calves, principally through targeted vaccination protocols. Testing can be carried out on live animals by blood sampling, swabs, or broncho-alveolar lavage; while on dead calves, post-mortem and PCR testing of lung tissue can yield valuable information.

Already the agricultural sector has made huge attempts to reduce and refine antibiotic use in our livestock, with once commonly used antibiotics no longer being available to the farming community. This trend in antibiotic availability and resistance, that is likely to continue in the future, and the devastating impact respiratory disease has on calf health, welfare and production, makes the old adage that ‘prevention is better than a cure’ more apt than ever before.

Unlike Covid where the scientific community worked tirelessly to develop a vaccination as the population struggled with lockdown restrictions, numerous vaccines are readily available through your veterinary surgeon to help prevent pneumonia in calves.