FISH ARTICLES: COLUMNARIS DISEASE
(Flexibacter columnaris, Cytophaga columnaris, Bacillus
columnaris)
In many cases, we receive calls from customers stating that they
have white wavy worm-like parasites attached to the glass in the
aquarium that tend to sway back and forth with the water circulation
in the aquarium. Often, the fish do not seem to be
affected at this stage. Given time for this disease to spread,
the infestations usually begin on the fins, which usually become
frayed and ragged. The disease will spread to the skin,
eventually causing ulcerations and irregular areas of epidermal
loss. Aeromonas hydrophila is commonly present in advanced
lesions and contributes to the pathology.
In the gills, Flexibacter Columnaris will color them light to
dark brown and you will also notice some necrosis. On the
skin, the fish will appear to have mold growing on it, with a slight
cottony look, due to a fungal infection that has attacked the
lesions and ulcerations. The lesions and ulcerations in
advanced stages are usually infected with a secondary motile
aeromonad. So as you can see, here is a situation where
you have multiple infections present.
Flexibacter Columnaris can persist in water for up to 32 days
when the hardness is 50ppm or more, but a hardness of 10ppm reduces
viability considerably. The addition of carbon to the system
increases the survival of this disease in hard water, but this is
not the case in soft water.
Columnaris is prevelant in systems with high organic loads,
crowded conditions, handling and low dissolved oxygen content.
Lesions generally develop in 24 to 48 hours following handling,
followed by death at 48 to 72 hours if not treated.
Treatment and Control:
For a purely external infestation, when there are not any
secondary bacterial infections present, Potassium Permanganate or
Forma-Green will work well.
In cases of multiple infections, it is suggested to give the fish
a bath in Postassium Permanganate or Forma-Green and thereafter,
treating with antibiotics such as: Oxytetracycline, Oxolinic Acid,
or a sulfa drug combination such as TMP Sulfa. The antibiotics
will need to be used on the fish for 10-14 days depending on the
severity of the infection. The antibiotics may either be used
in the water (as a long term bath), or mixed into the feed
(suggested). By mixing the antibiotics into the feed, you may
continue to treat the fish externally with the Potassium
Permanganate or Forma-Green. This treatment strategy will work
well if started in the early stages of this disease.
As with all diseases of tropical fish, proper maintenance and
water quality are the key to success.
Thank You and Good Luck,
Dr. Gary Aukes; Pharm D, and the staff of National Fish
Pharmaceuticals.
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