Dropsy (symptom set)

Causative agent: Primarily Aeromonas hydrophila — bacterial kidney infection causing fluid retention; also viral or parasitic causes

Dropsy is one of the most visually alarming conditions an aquarium hobbyist can encounter — a severely bloated fish with scales protruding outward in all directions like a pinecone is a hallmark sign of advanced dropsy. It is important to understand that dropsy is not a disease in itself but a collection of symptoms that indicate severe internal organ failure, typically caused by a bacterial infection of the kidneys resulting in fluid accumulation. Unfortunately, by the time the pinecone appearance is visible, the prognosis is often poor. In Australian freshwater aquariums, goldfish and bettas are the most frequent victims, often triggered by sudden temperature changes, poor water quality, or a compromised immune system. Early-stage dropsy — where the fish is slightly bloated but scales are not yet raised — can respond to antibiotic treatment with Aristopet Aquaricycline and Epsom salt baths. Any fish showing dropsy symptoms should be isolated immediately to a hospital tank, and the main aquarium should undergo a full water change.