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.

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Goldfish

Bacterial Diseases in Koi & Goldfish

Bacterial diseases are among the most common and serious health challenges facing koi and goldfish keepers worldwide. Caused…

Moderate To To To Severe

Freshwater Tropical

Columnaris

A highly contagious bacterial infection (Flavobacterium columnare) presenting as white/grey patches, often on the mouth, fins, or gills.…

Severe

Freshwater Tropical

Hexamita (Hole-in-the-Head)

Intestinal flagellate parasite causing pitted lesions on the head and lateral line, especially in cichlids and discus. Often…

Moderate

Freshwater Tropical

Swim Bladder Disorder

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

Moderate