Dropsy – Swollen belly, swollen fish, spiky scales Dropsy is a common term for the buildup of fluid inside the fish body cavity or tissues. It’s a symptom rather than a disease and can indicate a number of underlying diseases, including bacterial infections, parasitic infections, or liver dysfunction.

  • Description: The term dropsy does not refer to a particular disease but to a symptom – much like a cough is a symptom of a disease – that dramatically swells the abdomen of the fish (swollen belly) and raises the scales (spiky scales) due to fluid accumulation. Not to be confused with pregnancy or the consequences of temporary overfeeding, which do not cause scales to rise.
  • Possible associated symptoms: Pale color, apathy, loss of appetite, respiratory problems, sometimes ulcer and redness on the abdomen, abnormal swimming (the fish is tilted forward), swelling of the eye.
  • Direct causes: Aeromones hydrophila bacteria, Pseudomonas fluorescens, vibrio or even viruses. More rarely, a food imbalance (e.g. food too rich in protein) often linked to poor water quality.
  • Contributing factors: Stress factors (poor hygiene or acclimatization or inadequate nutrition). Check the water quality: it should have 0 ammonia, 0 nitrite and low nitrate.
  • Contagious: If the dropsy is of bacterial origin it is then contagious. It is recommended to isolate the affected fish in a hospital tank.
  • Severity: Dropsy reveals advanced renal dysfunction and is therefore very severe. Action must be taken as soon as possible to optimize the chances of recovery. Secondary infections are also very common (e.g. fungi).
  • Dropsy Treatment: Commercial antibacterial treatments: API Melafix, eSHa 2000, Interpet Disease Treatment, Sera Baktopur, or veterinary prescription (antibiotics).
Fish with dropsy (swollen belly)

Dropsy: the cone-shaped scales are caused by the accumulation of liquids under the abdomen.

Fish with dropsy

Many thanks to Virginie for these 2 photos.

Exclamation markImportant: do not forget to remove the activated charcoal during the entire treatment (as it will absorb the medication). It can be put back in the aquarium at the end of the treatment to remove the residues.   Good hygiene and water quality can prevent the re-occurrence of this disease.
Exclamation markImportant: Whilst all care is taken to provide accurate information on this website, Web Goldfish accepts no responsibility in the case of mis diagnosis of diseases/ incorrect treatments or any other errors made. In case of doubt, please always consult a veterinarian.