FISH ARTICLES: BRANCHIOMYCOSIS
Infected fish show signs of asphyxia such as gasping. They
appear weak and lethargic. Die-offs can reach a mortality rate
of over 50% in some cases. The fish that survive, may be able
to re-generate their damaged gill tissue if treated properly.
This disease is seen in the blood vessels of the gill tissue, and
it obstructs the circulation of blood through the gills, which makes
the gills lose their bright red color. The gill tissue becomes
mottled with patches of brownish discoloration due to hemorrhages
mixed with whitish areas of disrupted blood flow, resulting in
necrotic tissue. In some cases, the necrotic areas may slough
off and allow the gills to be invaded by a secondary disorder such
as a Saproglenia fungus.
Gill infection with Saprolegnia fungus looks almost
identical to Branchiomyces. This suggests that
Branchiomycosis may belong to the family "Saprolegniaceae".
Mycotic infections in goldfish and koi are mainly associated with
stress or injury. Infection with Branchiomyces is rapid, and
is mainly caused by algal blooms, overcrowding, high water
temperatures, and high levels of ammonia in the pond.
Prevention of Branchiomycosis can be accomplished by maintaining
good water quality, removing dead fish and preventing the
accumulation of decomposing organic matter. Decreasing feed,
and improving water flow to prevent the build up of ammonia are also
crucial. Thinning out fish to prevent crowding and stress
should also be practiced.
Treatment and Control:
A long term bath in
Acriflavine Neutral or
Forma-Green for seven days helps this condition. You can
also give the fish a one hour dip/bath in
Benzalkonium Chloride. Make sure to use a holding tank
when applying these treatment strategies. The use of the above
products in the pond will destroy the nitryfying bacterial bed which
prevents ammonia from being developed in the pond.
Water changes and the reduction of algae with the use of a
nitrifying facultative bacteria like
Aqua
Gold can prevent Branchiomycosis and many other diseases like
Aeromonas (hole in the side disease) from developing in Koi ponds.
Remember: Water quality is key, in any environment that contains
tropical fish.
Thank You and Good Luck,
Dr. Gary Aukes; Pharm D, and the staff of National Fish
Pharmaceuticals.
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