Disease Management

Aquarium fishes develop diseases due to poor environmental condition. Preventing disease is much more economical than providing expensive treatments following disease outbreak. Following steps can be taken to prevent fish diseases.

• Provide adequate and non-polluted water
• Provide sufficient space
• Provide adequate and balanced feed
• Prevent high temperature fluctuations
• Remove dead fish, faecal matter routinely
• Intermittently clean and disinfect the system
• Always maintain compatible species
• Avoid unnecessary handling
• Control internal and external parasites
• All new incoming fishes should be quarantined from resident stock
• Separate the infected fishes
• Provide adequate nursing for diseased fishes

Common disease of ornamental fishes and their treatments

Symptoms	Disease	Causative agent	Treatment	Observations
Pinhead size white spots on the body and fins	Ichthyophthyriasis	Protozoan parasite (Ichthyophthirius)	Increase the temperature and treat with 5% methylene blue (1 drop/litre), treat the fish for 1 week	Contagious, observed during sudden drop of water temperature
White spots smaller than above	Oodinium	Unicellular parasite (mono flagellate)	Copper sulphate 0.1 mg/litre for 10-15 min bath	Contagious
White clumps with cotton like appearance	Saprolegniasis	Fungi including Saprolegnia	1 tsp salt/2 litres water, 1-2 drops of 5% methylene blue or malachite green 2 mg/litre for 30 min dip or 0.1 mg/litre for permanent bath	Favoured by wounds
Swollen eyes	Exophthalmus	Bacteria, virus, fungi, sometimes together	1% silver nitrate on poped eyes followed by 1% potassium permanganate	Treatment is difficult
Gradual disintegration of fins	Pseudomoniasis	Bacterial disease	Surgical removal of ragged portion by a fine sterilized scissors, paint the cut wounded portion by iodine solution. Repeat the same at 12 & 24 hr	Unusual swimming behavior
Swollen abdomen erected scale	Dropsy	Bacterial disease	No known cure. Antibiotics may be tried.	Contagious, difficult to treat
Opercula sticking out, unusual swimming, tiny flukes on the gills	Gyrodactyliasis	Parasite fluke, Gyrodactylus	Formaldehyde 5-6 drops/litre water dip treatment for 10 min. Repeat for 3 days	Not easy to detect
Red patch in the body	Argulosis/ Learnaeasis	Argulus/ Learnaea ectoparasite	Physical removal of parasites, 15 min bath in 1-2% potassium permanganate, painting the region with iodine soln. Repeat the same after 12 & 24 hr	Violent rubbing due to irritation

Chemicals used in treatment

Iodine: Diluted by addition of an equal amount of water to produce a half-strength solution.
Malachite green: Stock solution prepared from zinc-free grade by adding 500 ml distilled water to 1 g malachite green.
Methylene blue: A stock solution is made by adding 1 g medical grade methylene blue to 100 ml warm distilled water.
Potassium permanganate: A stock solution is made by thoroughly dissolving 1 g crystals in 99 ml warm distilled water.