Amy Stanton, DVM, from OntarioVeterinaryCollege’s Department of Population Medicine at the University of Guelph, says emphasis on BRD has been focused on early detection of disease and prevention. While these areas are important, the disease probably won’t be eliminated anytime soon, so we need to determine best practices for caring for sick animals and facilitating their recovery.

While the costs of treatment and prevention of BRD are significant, perhaps the most underestimated cost of this disease is the long-term effect on the health and growth of calves. Some of these costs include decreased growth, delayed time to first calving, and increased risk of dystocia. In addition, calves treated for BRD before 3 months of age are 2.5 times more likely to die after 90 days of age than calves not treated for BRD.

Stanton says the importance of minimizing stress in order to prevent immune suppression is clear, but the practical methodology is not obvious. Some dairy producers are attempting to minimize post-weaning stress by removing dividers between individual stalls in the nursery to form groups prior to movement to the heifer rearing barn.  From economic and labor standpoints, most nursery barns are not designed to house weaned calves for extended periods of time, and producers make decisions with limited information. Researchers are exploring the benefits of grouping calves in the nursery one week prior to movement to a new facility, but this is only the first step towards creating practical science-based guidelines for producers. Factors such as the effective group size, and the timing as to when calves should be grouped, are unknown. 

Another important step is to identify indicators for detecting calves that fail to adapt to a new environment, and are at risk for the development of disease. Behavioral indicators of poor growth and subclinical disease are emerging, but more is needed to make this information practical for implementation by producers.

Early identification of sick animals can reduce the number of re-treatments necessary, which will reduce both the treatment costs and the length of time calves suffer. An easy system for long-term monitoring of BRD recovery is to chart growth to identify calves with poor performance. While this approach requires a change in the way many producers manage calves, there is a potential for many benefits.  By weighing calves at regular intervals, producers can identify calves those with poor gains and intervene. However, the appropriate interventions are not always clear.

“If lung damage is extensive, and the calf is suffering and unable to recover, euthanasia might be appropriate,” Stanton says. “If there is only minimal lung damage, and the calf is gaining at lower rates due to increased energy demands or a lower dominance status, moving affected animals to a less competitive environment could help calves recover.”