bacterial systemic · freshwater tank

Dropsy (Edema)

Dropsy (edema) is a fish disease where fluid accumulates in the body cavity, causing the abdomen to swell and scales to protrude (pinecone appearance). Usually a symptom of bacterial kidney infection or organ failure.

Reviewed by Fast Aquatics husbandry team · Updated May 2026
Severity: High - often fatal if pinecone effect is visible

Symptoms

What causes it

Bacterial infection (typically Aeromonas), poor water quality over time, parasites, or genetic predisposition.

Treatment options

Always treat in a separate quarantine tank.

Kanamycin + Maracyn 2. Combo treatment in hospital tank for 7-10 days. Most effective for early-stage dropsy.
Epsom salt. 1 tablespoon per 5 gallons in hospital tank. Helps reduce internal fluid retention.
Quarantine + clean water. Mild cases can recover with isolation and pristine water alone. Advanced dropsy is usually fatal.

Prevention

Maintain pristine water (zero ammonia/nitrite, low nitrate), feed varied diet, avoid stress.

Frequently asked questions

What does Dropsy (Edema) look like?

Swollen abdomen. Scales standing out from the body (pinecone effect). Bulging eyes.

What causes Dropsy (Edema)?

Bacterial infection (typically Aeromonas), poor water quality over time, parasites, or genetic predisposition.

How is Dropsy (Edema) treated?

Kanamycin + Maracyn 2: Combo treatment in hospital tank for 7-10 days. Most effective for early-stage dropsy.

Can Dropsy (Edema) be prevented?

Maintain pristine water (zero ammonia/nitrite, low nitrate), feed varied diet, avoid stress.

How fatal is Dropsy (Edema)?

High - often fatal if pinecone effect is visible

Related

Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.