The problem surfaced when an increase in abortions and open cows became apparent. On the surface it appeared that this was the extent of the losses until epidemiologists and ag economists from Ohio State conducted a detailed investigation to more completely understand the total economic impact of such disease problems. The results of their detailed study found that the abortions and open cows were just the tip of the iceberg. The real financial loss came in decreased milk production, in part from cows that did not necessarily show clinical signs of disease. That's a sizable price to pay for a problem that could have been avoided if a strong biosecurity plan had been in action.
Prevention is the best treatment.
I recently visited a large western dairy where questions about the efficacy of certain vaccines became the topic of interest. What had become apparent to them was that their abortion rate had progressively climbed from 10 abortions per month to upwards of 50 per month. Their question to me was regarding the efficacy of certain vaccines and how long the vaccines were expected to last. Vaccination programs, no matter how strong, cannot be expected to be the sole source of herd protection. At the time of my visit, the veterinarian had not yet determined the cause of the abortions and the investigation was continuing.