Goldfish Illness: What Are The Main Culprits?

maintaining a good water quality is vitally important to keeping healthy fish
maintaining good water quality is vitally important to keeping healthy fish

Goldfish illness is very common and sometimes fatal. However, if the symptoms are detected early and correct treatment given, the goldfish can make a complete recovery. Diagnosis of the illness affecting your fish is an important part of overall goldfish care.

Causes of fish illness can be bacterial, fungal, viral, parasitic diseases, physical ailments, protozoan diseases. The most common maladies seen in home aquariums are either bacterial or parasitic in origin. Fungal is sometimes seen and occasionally physical ailments.

4 main cuprits of goldfish illness: Ulcers, dropsy, white spots, bacterial infections.

When goldfish illness strikes your tank your fish may display behavioral symptoms such as:

Clamped fins
Body shaking
Repeated scratching against the objects in the tank
Gasping at the surface
Hiding in corners
Swimming abnormally
Breathing difficulties
Sitting on the bottom of the tank


These are caused by pseudomonas and aeromonas bacteria. Symptoms are pinky-white open wounds and sometimes the fish has secondary infections caused by fungi and other bacteria. This is generally caused by very poor water quality or excessively high PH levels. It mostly affects newly imported goldfish.

Treatment: Test if the water has ammonia and nitrates. Change the water to reduce the pollution level. Goldfish lose a lot of salt quickly through their open wounds, so add salt to the aquarium at a rate of two to three grams per liter along with an anti-ulcer treatment.

Click here to buy aquarium salt to treat your fish for ulcers.


Caused by bacterial infection, viral infection, nutritional and metabolic issues. Symptoms are swelling of the body cavity due to a build-up of fluid. The scales become raised giving a pinecone-like appearance. Poor water quality, particularly the presence of ammonia and nitrates can aggravate the problem. This is confined to individual goldfish. It is important to isolate the sick goldfish to prevent disease spreading to other fish.

Click here to find out more about Dropsy.

Treatment: To avoid dropsy, test and improve water conditions immediately by adding aquarium salt at a dose of two to three grams per liter to prevent the salt loss. It can be difficult to treat and requires a broad spectrum anti-bacterial treatment. One product I have often used is Tetra 8.45-Ounce AquaSafe Water Conditioner with BioExtract.

Click here for link to this treatment product.

White Spots

White Spots are caused by parasites infecting the goldfish. The signs to watch for are small white spots on the skin, fins, and gills. The spots are about the size of a grain of sugar. It’s caused by stress related issues such as poor, incorrect water conditions, unstable water temperature and general poor husbandry. Sensitive goldfish species may develop white spots as a result of being introduced to a new aquarium.

Treatment:  Ensure the water is free of pollution and isolate the cause of stress. To avoid white spot disease in goldfish, treat promptly with an anti-parasite medication.  For best results, you can try Imperial Garden Products OSI Fish White Spot Ick Terminator 7oz.

Click here for this product:  Imperial Garden Products OSI Fish White Spot Ick Terminator 7oz.

Click here to buy this aquarium salt for treatment.

Bacterial Infection

Caused by aeromonas and pseudomonas bacteria. The symptoms are ragged fins with signs of infection, open sores, and reddening of the skin or fins. Bacterial infection is mainly caused by poor water conditions, especially the presence of ammonia and nitrates. Wounds may occur as a result of fighting or poor handling when transporting the goldfish.

Treatment: Improve the condition of the water and treat promptly.

There are many other diseases that can affect your fish.

In summary, poor water conditions and improper handling of the goldfish contribute greatly to goldfish illness. Early detection of symptoms and implementing the appropriate treatment is imperative to provide the best outcome for your fish.