Dropsy in Koi: Symptoms, Causes, and Emergency Treatment

Dropsy in Koi: Symptoms, Causes, and Emergency Treatment

A female koi, initially tubby, has become hugely swollen over two weeks, eats but moves slowly, and appears uncomfortable. The owner asks about dropsy.

What Is Dropsy?

Dropsy is a symptom, not a disease: the fish's body swells due to fluid accumulation, causing scales to protrude (pinecone appearance). It results from internal bacterial infection, often triggered by poor water quality, egg binding, or organ failure.

Distinguishing from Kidney Enlargement

Kidney malfunction causes slow, gradual swelling without protruding scales; fish may live longer. Dropsy progresses rapidly and is usually fatal within weeks.

Immediate Actions

1. Test water for ammonia, nitrite, pH, and temperature.
2. Quarantine the fish in a hospital tank with pristine water.
3. Epsom salt bath: 1/8 teaspoon per 5 gallons to help reduce fluid retention.
4. Antibiotics: Broad-spectrum (e.g., kanamycin, erythromycin) if bacterial infection suspected.
5. Consult a fish veterinarian for accurate diagnosis and injectable antibiotics.

Photos of dropsy vs. kidney enlargement: Dropsy Photos, Enlarged Fish Photos.