For decades Halamid® is being used to keep the gills from salmonids clean. For that reason Halamid® is essential to the aquaculture industry.
The gills of salmonids can easily be infested by Flavobacterium branchiophilum which is a Gram-negative bacterium present in most freshwater environments. Even if such infection could occur in free-ranging fish it is rarely lethal and the cause of mortality therefore has to be found in the environmental conditions of intensively reared fish. Stress has been mentioned as one of the causative agents but it seems more likely that the bacterial pressure (the amount of bacteria present on the fish outer surface) plays a bigger role. Preventive use of Halamid® makes therefore a lot of sense.
In fact the ‘hairs’ of the ‘Flavo’ bacterium (the fimbriae) with which it attaches to the gill surface, cause lesions and further damage to the cells in the gill surface, leading to impaired blood circulation. Moreover the gills start to produce mucus to fight against the infection. All of this leads to insufficient oxygen uptake and mortality. The real risk is in the speed of this process. Mortality can occur within 24 hours from the first signals.
An experienced farmer easily recognizes the clinical signs of BGD: lethargy, loss of appetite, swimming high in the water and in a tilted position, signalling difficulty in ‘breathing’. The chances for successful curing all depend on an adequate and timely response with Halamid®.
Consequently farmers look beyond treating the symptoms. They know when the risk for elevated levels of ‘Flavio’ bacteria is higher and start treating preventively with Halamid®. This will keep the gills clean from large scale infestation and prevents mortality due to BGD.
In recent years Axcentive research has shown that keeping the bacterial pressure under control is more important than you might think. In tropical fish farming, Vibrio bacteria for example are rarely the cause of mortality, but they create the conditions for other causative agents (eg. viruses) to attack. Prevention is always better than curing….