ecisions to treat are based on a clinical sign (scours, difficulty breathing, fever, a discharge) and not on an actual diagnosis. It is important that you and your employees have worked with your veterinarian to develop good criteria for deciding to treat. The challenge is to develop sound treatment approaches so that antibiotics are targeted and appropriate.
One of the most controversial uses of antibiotics will be the blanket use (all animals in an age or production group) to treat or prevent disease. Two dairy situations are dry cow therapy and medicated calf replacer. The evidence for using blanket dry cow therapy is strongly supportive, and there is little or no evidence that its use results in the development of resistant bacteria. This is not true for the blanket use of medicated calf replacer. There are a growing number of studies that show no benefit to feeding calves antibiotics. Calves fed antibiotics have very resistant gut bacteria, there is little evidence that the antibiotics have value in preventing diarrhea, and calves that have received adequate colostrum and fed antibiotics are more likely to have diarrhea than similar calves not fed antibiotics.
When calves are dying, the instinct is to grab for that bottle of antibiotics. At the moment, that may seem to be the best decision, but over time what was a judicious decision becomes a habit and given time and circumstances may no longer be a good decision.
We all share in the responsibility to protect the value of antibiotics for treating animal and human disease. Developing judicious use guidelines that can be applied by you and your employees is an obligation that we have as partners in public health.