Fat Goldfish- All that You Want to Know

    Fat Gold fish

    Fat Goldfish

    If your goldfish suddenly got fat to the extent that it appears to explode at any moment, then it must be due to Dropsy. Dropsy is more of a symptom that indicates underlying health problems such as bacterial infection, a parasitic infection, or liver dysfunction. Generally, fluid gets accumulated in the tissues and abdominal cavities of goldfish, making the area swollen like a balloon. The condition is severe and can shut down the kidneys and spleen, disabling them from eliminating water build-up from the fish’s body.

    Other conditions such as swim bladder disorder, overfeeding, digestive issues, and a bad diet can also make your goldfish appear fat. So, before you diagnose the condition as Dropsy, make sure you look out for symptoms.

    If your goldfish is suffering from Dropsy, you will notice the following symptoms:

    Abnormal scales

    As the internal organs of the goldfish swell, it changes the layout of their scales. With Dropsy, the scales do not lay flat on the body; instead, they protrude outwards, making the goldfish looks like a pinecone.

    Swollen Eyes

    The infection can accumulate fluid in the organ, and some of these excess fluids start to leak around tissues and cause pressure behind the eyeballs, making them bulge outwards.

    Pale feces

    With Dropsy, fishes stop eating their food, resulting in pale feces that usually does not contain any solid particles. Besides, fishes start to secrete mucus through their feces, making them look pale or stringy.

    Swollen Anus

    If the Dropsy is caused by enteric redmouth disease, it will swell the anus of the goldfish, making it appear red.

    Curved spine

    The fish’s spine may appear curved with fluids accumulating inside the organs.

    Closed fins

    Since Dropsy makes the fish unable to swim, they often hold their fins tight to the body.

    Red Skin or Fins

    If the Dropsy is caused by Aeromonas infection, you will notice signs of hemorrhaging on or under the fish’s skin.

    Besides, Dropsy can make your goldfish too lazy to swim or move, and they may even refuse to eat their food. Therefore, most fishes affected by this condition are noticed to hover at the bottom of the tank.

    If you notice any of the above signs in your goldfish, you must seek immediate help.

    What can cause Dropsy in goldfishes?

    Goldfish bodies contain more salt than the salt level in the water level they live in. As a result, they lose salt in the water, causing water to pass through their bodies. If they lose too much salt, their body will start absorbing water. Therefore, goldfishes need to maintain their salt levels for survival.

    I have to take salt and expel water from their bodies continuously. This is an entirely normal process controlled by their kidney.

    However, Dropsy occurs when a goldfish’s kidney function starts to deteriorate. If their kidney stops eliminating water, their body will begin bulking like a water balloon.

    There are various reasons why the kidney of the goldfish stops functioning. It could be due to an infection or an injury.

    The most common reason behind Dropsy is the Aeromonas bacteria, a gram-negative bacteria generally found in aquarium habitats. The bacteria only cause severe infection to fish with a compromised immune system. This can happen due to several reasons, such as:

    • Stress caused by transportation
    • Aggressive behavior of other fishes in the tank
    • A significant drop in water temperature
    • Spikes in ammonia or nitrites
    • Poor quality water
    • Other underlying diseases and infections

    Usually, single or short-term stress does not affect the immune system of a goldfish. If a goldfish is exposed to stress for a long term, this could trigger an impaired immune system.

    Diagnosing Dropsy in Goldfish

    People often confuse Dropsy with swim bladder disorder or flip over as symptoms from both the diseases resemble some similarities such as curved spines, swollen bellies, and general ailments. The classic symptoms of Dropsy are a swollen belly with protruded scales, skin lesions, and a reddened anus.

    Differentiating Dropsy from swim bladder disorder is often difficult. As a result, aquatic veterinarians often observe the physical and behavioral symptoms of the fish. They also conduct a lab test to determine the infection type and administer the right antibiotic for treatment.

    Dropsy Treatment in Goldfish

    A step-by-Step treatment plan for Dropsy in Goldfish

    Step 1: Quarantine

    Move the fish to another tank as earliest as possible before it infects the other fishes.

    Step 2: Add Salt

    Restore the osmotic balance of the fish by adding one teaspoon of salt per gallon of water to the fish tank. Saline water helps improve the fish’s blood salinity.

    Step 3: Clean the Water

    Keep the water clean by partially changing the water every week, followed by step 2.

    Step 4: Offer Quality Food

    Offer high-quality food to the ill fish.

    Step 5: Treat with Antibiotics

    Treat the ill fish with antibiotics either via food or by adding them to the water. Since gram-negative bacteria mainly cause it, you need to treat the fish with broad-spectrum antibiotics such as Maracyn-2. A course for ten days is ideal for clearing out the infection. However, make sure to follow the directions as instructed by the veterinarian

    Step 6: Observe

    Keep the fish under your observation several days after the symptoms disappear.

    Step 7: Monitor other fish

    Even though you quarantine the affected fish, make sure you continue observing the conditions of other fishes in the original tank. Make sure to do a water change and treat them with good food and antibiotics (if prescribed).

    How to Prevent Dropsy in Goldfish?

    Prevention is always better than cure, and you should abide by this statement. Make sure to create a stress-free environment for your fish, as this is the primary trigger factor for Dropsy. The most common cause of infection is poor water quality. So, keeping the tank water clean should be your priority.

    • Test the quality of water in your aquarium
    • Change the water regularly
    • Keep the tank and filters clean
    • Use a gravel vacuum to clean wastes efficiently
    • Do not overfeed your fishes
    • Do not overcrowd the tank
    • Keep aggressive fishes away from goldfishes
    • Choose quality foods for your fishes


    Remember, Dropsy itself is not a disease but a sign of an underlying problem. Treating Dropsy in goldfish is challenging, but it can be treated with early diagnosis and isolation followed by proper treatment.

    The infection in Dropsy is not easily cured. Therefore, most experts recommend euthanizing the fish and preventing the disease from spreading to other healthy fishes in the tank.

    So before you start treatment, you must accept that the mortality rate in Dropsy is high. The success of a treatment is only possible if the symptoms are detected at the early stages of the infection.