Goldfish Diseases By Symptoms And Treatment

Recognising symptoms early for treatment intervention gives your sick fish the best chance of recovery
Recognising symptoms early for treatment intervention gives your sick fish the best chance of recovery

Goldfish are prone to diseases or infections, which can cause early death.

One of the main reasons goldfish get sick is because of a dirty bowl, tank or aquarium. When their tank is dirty, filtration, water and oxygen levels become low. This leads to the temperature becoming either too warm or too cold. Breathing is made difficult for the fish.

All fish fall sick and are afflicted by disease and problems occasionally. Many goldfish unnecessarily die because their owners do not recognize the different diseases.

Learning how to detect and diagnose disease in the early stages will greatly improve the outcome.

This is a summary of 7 diseases and treatments


Also known also as freshwater white spot disease or Ichtyopthirius

  • This is caused by a microscopic parasite which is known as the Ichthyophthirius multifiliis.
  • The parasite attach themselves to the goldfish which then forms the white spots.
  • Symptoms of this disease include visible white dots covering your goldfish body, rapid gill movements in later stages of disease and your fish frequently rubbing itself against objects in the tank.

Click here to read more about Ich and recommended treatments you can do for your fish.


This disease can be treated by vacuuming the gravel and then treating the whole fish tank with salt.


  • Symptoms of this disease include flashing, irritation, difficulty in breathing and lethargy.
  • With flukes, a gill or body scrape is important to diagnose.


Treat flukes by using Praziquantel.

For a full description of flukes and treatment for aquariums and ponds, click on this link.

How To Take Care Of Your GoldfishTail or Fin Rot

  • Tail or Fin rot is also known generally as necrotic loss of fin tissue and is caused by stress and poor environmental conditions.
  • Symptoms of this disease include ragged fins and a hole appearing in the middle of the edge of the fin.


Tail or Fin Rot can be treated by melafix, using salt, and hydrogen peroxide bath.

Copepods, Lice and Anchor Worms

  • In diagnosing this disease there is the advantage of parasites being large enough to be seen with the naked eye.
  • Symptoms of this disease include louse’s eye spots on the bump when watched closely, grey – green to brownish raised spots on the goldfish.


Treat your fish by removing parasites with tweezers then cleaning the sore with iodine or hydrogen peroxide to prevent another infection.

You should also go further and treat the whole fish tank with dimilin.


  • Flex is caused by bacterium, although the disease appears as if it is a fungus.
  • Symptoms include cotton like growths. It has also been described as looking like mould.


This condition is treated by using common water antibiotics like Spectogram, Maracyn, or salt.


  • Not a disease but painful nonetheless for your goldfish.
  • It is caused by a diet without variety or by feeding your fish with too many starchy foods.
  • Symptoms of this disease include difficulty passing excrement.


Change your goldfish diet by including more vegetables. Use different varieties like spinach and peas. You might want to try tubifex worms as well.


  • This is a very dangerous disease and to some levels it cannot be treated.
  • Symptoms include swollen eyes, swollen belly and scales that protrude.

Click here to read more about Dropsy and 3 treatments that have proved effective that you can do at home.


For treatment of  dropsy and all other goldfish diseases, ideally consult your veterinary clinic in order to prevent your goldfish from an untimely death.

Your vet can do frequent check ups on your goldfish.