Dropsy: symptoms, treatment, prevention

Dropsy is a symptom complex of fluid accumulation in the body cavity caused by systemic bacterial infection or organ failure; pineconing scales indicate poor prognosis.

Overview

Dropsy is not a single disease but a symptom complex of osmoregulatory failure, most often caused by systemic Aeromonas or Pseudomonas infection. Fluid accumulates in the abdomen, scales lift outward in the classic pinecone pattern, and the prognosis is poor once pineconing is visible.

Symptoms

• Pineconing scales
• Swollen abdomen
• Popeye
• Lethargy
• Anorexia
• Loss of color

Causes

Chronic stress, persistently poor water quality, prolonged overfeeding and underlying organ disease allow bacteria to cause systemic infection that disrupts osmoregulation.

Diagnosis

Pineconing scales with a swollen abdomen are pathognomonic. Differentiate from simple constipation (no pineconing, no scale lift) and from egg-bound females (lateral swelling only, no systemic signs).

Treatment

Even with intensive therapy the prognosis is poor once pineconing is visible. The realistic goal is to relieve fluid build-up and treat the underlying bacterial infection.

Quarantine

Move affected fish to a hospital tank with stable parameters and strong aeration. Treating the main tank with antibiotics risks destroying the biofilter and harming healthy tankmates.

Medication

1. Kanamycin sulfate in medicated food for 10 days.
2. Magnesium sulfate (Epsom salt) at about 1 tablespoon per 20 litres as an osmotic diuretic in the hospital tank.
3. Metronidazole in food to address possible protozoal coinfection.

Recovery

If swelling subsides, continue supportive care with high-quality food and pristine water. Many cases nevertheless end in mortality once organs are damaged.

Prevention

• Minimise chronic stress
• Stable water parameters
• Avoid overfeeding
• Balanced diet
• Early intervention at first symptoms