Large amounts of bee feces spotted on the front of the hive, which can be a sign of dysentery, may be one problem you will face this winter. Bees will make cleansing flights on warm days and may stain the front of the hive. So little feces spotted on the hive is fine. Dysentery is not a reliable indicator of this disease. Nevertheless, if you see dysentery it wouldn't hurt to feed Fumidil B just to eliminate possible Nosema problems.
Poor quality feeds .
Honeydew and brown sugar are suspected of encouraging dysentery in bees. If these make up a substantial part of your bees' overwintering stores it may cause trouble. The higher concentration granulates more slowly, but it also costs more. Fermented honey . Try to avoid feeding fermented honey to your bees.