Disease library

Fish disease library

Every disease, parasite, and infection in our knowledge base. Tap the keywords to narrow the list — the page updates with a clean, shareable URL.

8 conditions

Clear all filters

Freshwater Tropical

Aeromonas (Ulcer Disease)

Bacterial infection causing open ulcers, hemorrhagic patches, and red sores. The #1 cause of mortality in koi ponds…

Critical

Freshwater Tropical

Velvet (Oodinium)

Dinoflagellate parasite producing a fine, gold-dust coating across the body. More lethal than ich; gill infection causes rapid…

Severe

Freshwater Tropical

Swim Bladder Disorder

Loss of buoyancy control — fish floats, sinks, or swims at odd angles. Common in fancy goldfish and…

Moderate

Freshwater Tropical

Lymphocystis Disease

Virus disease of aquarium fish. Key signs: wart-like, cauliflower-shaped, pinkish-white nodules on skin and fins (greatly enlarged virus-infected…

Mild

Freshwater Tropical

Bacterial Cold Water Disease

Bacterium disease of aquarium fish. Key signs: rtfs in fry: spiral swimming, exophthalmia, dark colouration, anaemia, splenomegaly; older…

Moderate

Freshwater Tropical

Bacterial Kidney Disease (BKD)

Bacterium disease of aquarium fish. Key signs: chronic, progressive: granulomatous lesions in kidney (creamy white nodules), spleen, and…

Moderate