Survey of veterinarians in 6 US states regarding their experience with nursing beef calf respiratory disease

Abstract

Bovine respiratory disease (BRD) is the leading cause of death of nursing beef calves 3 weeks of age and older, but little is known regarding risk factors for calf BRD. The objective of this survey was to describe observations and practices relevant to calf BRD by veterinarians in cow-calf practice. Recipients in Eastern (Georgia, Florida, and West Virginia) and Plains (Iowa, Kansas, and Nebraska) states were asked to complete an on-line questionnaire regarding events occurring between August 2011 and July 2012. A total of 574 veterinarians were solicited to participate; 61 (10.6%) returned responses suitable for inclusion, with an equivalent proportion responding from both regions. Respondents reported that 18% of their cow-calf clients recognized cases of nursing-calf BRD in the previous year, and 14% of their clients had at least 1 calf die of BRD. Infectious agents identified by antemortem or postmortem testing included Mannheimia haemolytica (60% of respondents); Pasteurella multocida (53%); Mycoplasma bovis (37%); bovine respiratory syncytial virus (33%); and bovine viral diarrhea virus (33%). Of responding veterinarians, 80% recommended or administered treatment for an outbreak of nursing-calf BRD in the previous year. Routine administration of respiratory vaccines to nursing beef calves was recommended by 87% of respondents. Respondents identified a variety of risk factors as potentially associated with calf BRD. Two of these, "introduction of cattle from outside sources" and "occurrence of diarrhea in calves", were also significantly associated with nursing-calf BRD in a previous survey of producers in the same states.