The incubation period for either F . branchiophila or C . Control Prevention Prevention of BGD in hatchery salmonids is difficult because the fish are constantly stressed. Sanitation and application of the proper cultural practices is helpful, but does not eliminate outbreaks. Prevention of BGD is more difficult in pondfishes than in hatchery fishes, because C . Treatment Several chemicals have been used to treat BGD in hatchery salmonids.
Caution is necessary because the margin of safety is narrow, particularly in soft water.
Another chemical is the herbicide Diquat. None of these chemicals are approved by the U. S . Food and Drug Administration for disease control in food fishes. In hatchery tests conducted by the National Fish Health Research Laboratory, one treatment effectively controlled BGD when it was given early in an outbreak. However, two or more treatments are required for advanced outbreaks.