The Discus Plague, also known as discus fish black disease is a fatal viral disease that affects discus fish, and some other American Cichlids. Discus plague is highly contagious, goes airborne, and get all tanks in the same room affected.

Discus Plague Symptoms

Discus that are affected by plague disease exhibit following symptoms:

  • Hanging in the dark corners near bottom or top of the tank
  • Getting dark in color
  • Leaning to one side or another at top or bottom of the tank
  • Peppering
  • Not eating, being shy, or hiding behind aquarium decorations and filters with clamped fins
  • Excessive mucus and slime coat production
  • Scratching and rubbing against aquarium objects; they may also start darting and twitching
  • Cloudy and/or smelly water due to large amount of slime coat and protein
  • Severe fin rot and/or columnaris
  • White patches and/or points on fish’s skin; these white spots usually are caused by secondary infections such as external parasites, bacteria and fungi


Viral diseases has no cure, and treatment is supportive. The goal is to help the fish by preventing secondary bacterial, fungal, and parasitic infections.

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