In a previous article, we reviewed the fact that hypocalcemia (milk fever) and ketosis are by far the two most important diseases to consider for early-lactation cows. I consider these to be “iceberg diseases,” meaning that we only see the tip of the iceberg (typically about 2 to 5 percent of all dairy cows that calve exhibit clinical symptoms for each disease). See Figure 1 below left. On the other hand, various research studies show, on average, the subclinical rates of these two diseases may average about 40 percent each in today’s dairy cows.