Bovine fatty liver syndrome is a metabolic disease of heavily lactating dairy cows. The ailment is sometimes called "fat cow syndrome", however, a cow need not be visibly overweight at calving time to be affected by fatty liver. Cows with fatty liver syndrome are more likely to suffer from periparturient problems such as milk fever, ketosis, mastitis and metritis. They tend to respond poorly to therapy and they often relapse. Their milk production is often reduced, they may have reproductive disturbances, and they may die.