Individual herds may experience exceptionally high rates (∼50%) of cystic ovary disease over a period of months. The difficult task of determining the cause of these multifactorial episodes should include addressing the following questions:
Is the diagnosis accurate; ie, are the structures being identified as cysts really cysts? (See the follicular cyst image in Cystic Ovary Disease and Cystic Corpus Luteum in Cows). The diagnosis can be confirmed via second opinion, determination of milk or plasma progesterone concentrations, ultrasonographic examination of the ovaries in suspected cases, and/or the observation of ovarian changes and time of estrous activity after treatment with prostaglandin products.
Has the palpation examination schedule for the herd changed? Initiating routine postpartum examinations for all cows and increasing the frequency of herd visits can result in the appearance of increased incidence.
Has the herd incidence of periparturient complications and stress increased? Cows that have problems around calving (twins, milk fever, dystocia, retained placenta, ketosis, etc) are much more likely to develop cysts. Attempts should be made to avoid these complications.
Has herd genetics been considered? It is well accepted that ovarian cysts are more common in certain genetic lines, and genomics now offers an opportunity for control.
Has the nutritional program of the herd been evaluated? Nutritional problems are frequently implicated as a risk factor for cystic ovary disease. Proper nutritional management of dairy herds is always warranted. The effects of the nutritional program should be monitored by use of a body condition scoring program as part of the effort to decrease ovarian cysts in problem herds.
Has the management of cows around the time of estrus been altered? Social and environmental changes may cause stresses associated with cystic ovary disease.
