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
Mycobacteriosis (Fish Tuberculosis)
A slow, chronic infection caused by Mycobacterium spp. Symptoms include emaciation, spinal deformity, and granulomas. Zoonotic risk —…
Critical
Freshwater Tropical
Freshwater Ich (White Spot Disease)
The most common freshwater fish disease. Tiny white spots resembling grains of salt cover the body and fins.
Moderate
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
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
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
Gill and Skin Flukes (Dactylogyrus & Gyrodactylus)
Parasite (monogenean flatworm) disease of aquarium fish. Key signs: increased mucus on gills/skin, flashing, gasping at surface, frayed…
Moderate
Freshwater Tropical
Hole-in-the-Head Disease (Hexamita)
Parasite (flagellated protozoan) disease of aquarium fish. Key signs: pinhole-sized pits on head that enlarge into cavities; lesions…
Moderate
Freshwater Tropical
Fin and Tail Rot
Bacterium (mixed/opportunistic) disease of aquarium fish. Key signs: ragged, frayed or eroded fin edges; white margins followed by…
Moderate
Goldfish
Asian Tapeworm Infection
Parasite (cestode) disease of aquarium fish. Key signs: heavy intestinal worm burden, emaciation, distended abdomen, anaemia, intestinal blockage;…
Moderate
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
Columnaris (Cotton-Wool Disease)
Bacterium disease of aquarium fish. Key signs: white-grey saddle-shaped lesion across back, frayed fins, mouth fungus-like white patches,…
Severe