The Pinecone Symptom
View the betta from above. If the scales stick out like a pinecone, the fish has dropsy. Internal fluid buildup pushes scales away from the body — by the time you see the pinecone effect, kidneys have likely already failed.
Earlier signs: bloated belly, lethargy, sitting on the substrate, sudden refusal to eat. These can also be constipation or swim bladder issues, but dropsy is the worst-case explanation and worth treating proactively.
Causes
Dropsy is caused by bacterial infection (most commonly Aeromonas) that damages the kidneys, leading to fluid retention. Risk factors: poor water quality, cold temperature, stress, old age, or feeding contaminated live food.
It is not directly contagious to other fish, but the underlying water issue that caused it can affect the whole tank. Test ammonia, nitrite, nitrate immediately when you see dropsy.
Treatment Protocol (Low Success Rate)
Move fish to hospital tank with clean water at 79°F. Add epsom salt (1 tbsp per 5 gallons) to draw fluid out. Dose Kanaplex or Furan-2 daily for 7 days. Feed minimally — daphnia or peas can help with constipation if that contributes.
Realistic expectation: 10-20% survival once pinecone is visible. The treatment is mostly to give the fish a chance, not a cure. If the fish is suffering and getting worse, humane euthanasia (clove oil overdose) is more compassionate than prolonged decline.
- ✦Do not move the fish unnecessarily — handling stresses dying fish.
- ✦Test water in the main tank to prevent the next dropsy case.