Goldfish
Parasitic Diseases in Koi & Goldfish
Parasitic infestations represent one of the most diverse disease categories in ornamental fish keeping. From the microscopic ciliate…
Mild To To To Severe
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.
Fish type
Symptom
Bloated Abdomen 2
Bloated belly 2
Clamped Fins 3
Cloudy Eye 1
Color Fading 1
Cotton Like Growth 1
Cottony Tufts 2
Darkened color 4
Dropsy 1
Emaciation 4
Erratic Swimming 7
Excess Mucus 3
Eye Discharge 1
Fin Erosion 1
Fin Rot 3
Fin Whitening 1
Flashing 4
Flashing / rubbing 8
Floating 1
Frayed Fins 6
Gasping at surface 4
Gill Damage 1
Gold Dust Coating 1
Gold-dust film 1
Granulomas / nodules 3
Head Pitting 1
Hemorrhage 1
Hemorrhaging 13
Lateral Line Erosion 1
Lethargy 19
Listless near bottom 1
Loss Of Appetite 7
Loss Of Balance 1
Mouth Erosion 1
Open Sores 4
Pale Gills 4
Pinecone Scales 1
Pop Eye 17
Rapid breathing 4
Rapid Gilling 4
Red Fin Bases 1
Red Ulcers 2
Scale Loss 1
Scratching 3
Sinking 1
Skin Erosion 1
Skin lesions 4
Spinal Deformity 2
Sudden death 3
Sunken Eyes 1
Swimming Sideways 1
Tissue necrosis 8
Ulcers 1
Visible parasite 1
Wart-like growths 2
White Fin Edges 1
White Grey Patches 1
White Patches 1
White Patches Gills 1
White Spots 5
White Stringy Feces 1
White Tail 1
Cause
Aeromonas hydrophila 1
Aphanomyces spp. 1
Argulus spp. 1
Bacteria 16
Branchiomyces spp. 1
Columnaris 1
Dactylogyrus spp. 1
Environmental 2
Fungus 3
Ichthyophthirius multifiliis 1
Lernaea spp. 1
microsporidian 1
Parasite 18
Pleistophora hyphessobryconis 1
Pseudoloma neurophilia 1
Pseudomonas fluorescens 1
Saprolegnia spp. 1
Trichodina spp. 1
Virus 14
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
Fin Rot
Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.
Mild
Freshwater Tropical
Streptococcosis
Bacterium disease of aquarium fish. Key signs: exophthalmia (often unilateral, 'pop-eye'), corneal opacity, spinning/spiral swimming, darkening, hemorrhages around…
Severe
Freshwater Tropical
Motile Aeromonad Septicemia (Ulcer Disease)
Bacterium disease of aquarium fish. Key signs: open red ulcers (especially in koi), hemorrhagic skin patches, distended abdomen…
Moderate
Freshwater Tropical
Enteric Redmouth Disease (ERM)
Bacterium disease of aquarium fish. Key signs: subcutaneous hemorrhages around mouth and throat (the 'red mouth'), darkening, exophthalmia,…
Severe
Freshwater Tropical
Enteric Septicemia of Catfish (ESC)
Bacterium disease of aquarium fish. Key signs: acute septicaemic: lethargy, head-up vertical floating, petechial hemorrhages on chin and…
Severe
Freshwater Tropical
Furunculosis
Bacterium disease of aquarium fish. Key signs: acute: rapid mortality without obvious external signs; chronic: characteristic 'furuncles' —…
Severe