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.

7 conditions

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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

Goldfish

White Tail Disease in Koi & Goldfish

White tail disease is a serious and poorly understood condition caused by microsporidian intracellular parasites that destroy muscle…

Moderate To To To 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

Cloudy Eye

Hazy or opaque film over one or both eyes — usually a sign of bacterial infection or chronic…

Moderate

Freshwater Tropical

Branchiomycosis (Gill Rot)

Fungus (true fungus) disease of aquarium fish. Key signs: rapid breathing, gasping at surface, gill necrosis with white/marbled…

Severe

Freshwater Tropical

Saprolegnia (Cotton Mold)

Oomycete disease of aquarium fish. Key signs: cotton-wool-like white or grey patches on skin, fins or eggs, often…

Moderate