Early recognition of disease symptoms is critical for successful treatment. Always observe your koi daily for behavioral and physical changes.
Behavioral warning signs:
Flashing (scratching against objects)Clamped or folded finsIsolation or bottom-sittingLoss of appetiteRapid gill movement (gasping)Jumping or erratic swimmingHovering at the surfaceCommon diseases and their signs:
Ich (White Spot): Small white dots like grains of salt on body and fins. Highly contagious.Flukes (Gill/Body): Flashing, excess mucus, clamped fins, gill irritation. Microscope scrape needed for confirmation.Columnaris: White or grayish patches, cottony growths, fin erosion. Bacterial infection.Dropsy: Swollen body with scales standing out like a pine cone. Often indicates organ failure.Ulcers: Open red sores on the body. Usually bacterial, often secondary to parasite damage.Fungus (Saprolegnia): Cotton-like white or gray growths, usually on damaged tissue.What to do when you suspect disease:
Do NOT treat blindly -- identify the problem firstTest water quality immediately (poor water is the #1 cause of disease)Document symptoms with photos and timelineIsolate severely affected fish if possibleConsult a koi veterinarian for diagnosis -- many issues look similarUse the Symptom Timeline Builder to create a shareable record for your vet