getting more common. This infection is a species jump from game fish, trout and
salmon where it causes many losses.
Ulcers are deep into the body wall and very large - they look
like the fish has been filleted in its latter stages.
This disease seems
to have got a grip in mud ponds in warmer climes.
The infectious agents
are aeromonas hydrofiller, aeromonas salmonicida and some strains of
This disease also occurs as a secondary infection after a
primary infection caused by skin flukes or other skin or gill parasites.
It usually occurs, or should I say starts, in the spring as
temperatures rise and is mainly encounted in poor water.
I find that
over feeding in the spring and inefficient filtration is one cause, whilst not
checking water quality is another. Also stripping filters out for a spring
clean before the water is warm enough to reseed them. In other words not
cleaning filters in September when water still has a high enough temperature to
The problem is this infection responds very poorly to any
treatments. I find success is around 20% and once holes is down to 5% (that's
just what the start of this disease looks like - holes, just like a heron