Freshwater

Dropsy
Symptoms: Swollen body; protruding scales; fish looks like a pincushion.
Cause: Organ failure from cancer and old age, or poor water conditions.
Treatment: Antibacterial given through medicated food. Improvement of
water quality through water changes also provides a little relief to afflicted
fish. Complete recovery from dropsy is rare.
Fin rot
Symptoms: Reddened or inflamed rays; torn, choppy, ragged, or disintegrated
fins. Your fish may look like it just swam through an electrical fan.
Cause: Fin rot is a highly contagious bacterial infection that, in its advanced
stages, can completely erode the fins and tail all the way down to the body.
Bad water quality and fin injuries are usually the main causes of this disease.
Fin rot is frequently followed up with a secondary fungal infection.
Treatment: Spot treat infected areas with gentian violet and use proprietary
medication (a treatment that is labled for one particular disease, such as
fungus cure, ich cure, and so on). Add 1 tablespoon of aquarium or marine
salt for each 5 gallons of water. Remove activated carbon from all filters
during the medication period. Frequent water changes are necessary to help
improve water conditions.
Fish louse
Chapter 11: Diseases and Treatments
Symptoms: Disk-shaped parasites attach to the skin. Ulcers often develop
close to the area of parasitic attachment. Bacteria or fungus problems may
follow after.
Cause: Crustacean parasite. After feeding on the skin, the adult parasite
leaves its host and lays gelatinlike capsules full of eggs on the substrate and
aquarium decorations. Often the eggs don’t hatch until the aquarium temperature
rises, and may stay in the tank for extended periods of time.
Treatment: Remove all parasites from the afflicted fish using a small pair of
tweezers. Dab any wounds using a cotton swab dipped in commercial
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