While a great deal of study has taken place on bovine respiratory disease (BRD) in feedlots, BRD also sometimes affects young calves, and less is known about the disease complex at that production stage. During the recent American Association of Bovine Practitioners conference, veterinarians provided some insight into pre-weaning incidences of BRD.
Dr. Russ Daly, from South Dakota State University, said pre-weaning BRD outbreaks are not predictable, and when outbreaks occur, within-herd incidence can be high. And, he says, outbreaks occur even in herds where calves are well-vaccinated at branding or turnout. Fortunately, he says, most affected calves respond well to treatment, and death loss can be kept to low levels with diligent monitoring and timely treatment.
Daly says the typical reaction to outbreaks among producers and their veterinarians is to fall into firefighting mode, just trying to gain control of the disease. While timely treatment is important, he also advises taking a systematic approach toward mitigating the disease — at the kitchen table rather than at the chute. He encourages veterinarians to sit down with their clients to compile information on the outbreak to gain understanding of how it occurred, resolve it and prevent future problems.
He suggests gathering information on the animals affected, their age at the time of infection, where they were located on the ranch and, when possible, other information such as identification of sick calves’ dams, age of the dams and dystocia scores. Also discuss time events such as herd-management dates, group movements, introduction of other animals to the herd and weather events around the time of the onset of clinical signs. The veterinarian potentially can use this information to determine how the disease established and spread within the herd.
BRD, of course, can involve several different pathogens including bacteria and viruses, and Daly encourages veterinarians to employ diagnostic testing in live animals and post-mortem examinations for any calves that die from BRD.