Goldfish are susceptible to a range of different diseases that can become fatal if they are not treated, with some of the most common diseases spawning from a type of fungus. There are fungal spores naturally present in the water column of an aquarium, but they can affect goldfish that are vulnerable due to open wounds, stress, or poor water quality.
Reviewed & Fact-Checked By
Dr. Paola Cuevas
Veterinarian, MVZ
Reviewed & Fact-Checked By
Dr. Paola Cuevas
Veterinarian, MVZ
The information is current and up-to-date in accordance with the latest veterinarian research.
It is important to learn about the most common fungal diseases that can affect your goldfish so that you know how to recognize the symptoms. This article will explain the different types of fungal diseases and how you can effectively diagnose, treat, and prevent them from occurring in your goldfish.
4 Common Goldfish Fungus Diseases
1. Gill Rot (Branchiomyces)
This type of fungus causes the gills of a goldfish to rot away. It can become fatal if not treated promptly because your goldfish relies on their gills to breathe normally.
Symptoms:
Grey and mottled gills
Respiratory distress
Torn and damaged gills
Rapid breathing
Treatment: Unfortunately there is no established treatment for this disease as it has a high mortality rate. Clotrimazole, copper sulfate, and formalin have been used for treatment with some success. In severe cases, euthanasia may be a kinder method for a goldfish suffering from this fungus disease. It is important to increase the amount of oxygen in the aquarium by using an aeration system so that the infected goldfish do not have to gasp at the surface to breathe easier.
Prevention: This fungus thrives in a warm environment, so you may want to gradually lower the temperature in your goldfish aquarium during treatment. Unfortunately, gill rot is usually fatal in goldfish and prevention is better than treatment. If you notice that your goldfish has damage to their gills, it is important to keep the aquarium conditions sanitary to prevent this fungal spore from attacking the damaged gills.
Grey and mottled gills
Respiratory distress
Torn and damaged gills
Rapid breathing
Grey and mottled gills
Respiratory distress
Torn and damaged gills
Rapid breathing
Treatment: Unfortunately there is no established treatment for this disease as it has a high mortality rate. Clotrimazole, copper sulfate, and formalin have been used for treatment with some success. In severe cases, euthanasia may be a kinder method for a goldfish suffering from this fungus disease. It is important to increase the amount of oxygen in the aquarium by using an aeration system so that the infected goldfish do not have to gasp at the surface to breathe easier.
Prevention: This fungus thrives in a warm environment, so you may want to gradually lower the temperature in your goldfish aquarium during treatment. Unfortunately, gill rot is usually fatal in goldfish and prevention is better than treatment. If you notice that your goldfish has damage to their gills, it is important to keep the aquarium conditions sanitary to prevent this fungal spore from attacking the damaged gills.
It covers everything from water conditioners to tank maintenance, and it also gives you full, hard copy access to their essential fishkeeping medicine cabinet!
2. White Fungus (Saprolegnia)
Also known as “cotton wool disease” this fungus causes fluffy white growths on your goldfish’s body. It eats away at their slimy coating which then leaves the goldfish’s body vulnerable to infection.
Symptoms:
Raised pale scales
White fluffy growths across the body
Slime trailing off the goldfish
Rapid breathing
Lethargy
White growths on the mouth
Treatment: A salt bath or dip every couple of hours is recommended to treat mild cases of white fungus disease. It is important to keep the goldfish in a treatment tank isolated from other goldfish as this disease is highly contagious. For more severe cases, methylene blue baths or machalite green dips can be effective at killing off this fungus. Pimafix has proven to be an effective treatment against white fungus disease.
Prevention: Gradually lower the temperature in the aquarium and ensure that you do regular water changes to improve the quality of the water. Avoid handling your goldfish or placing dirty hands and equipment into the water column.
3. Ichthyosporidium
This is an internal fungal infection that affects a goldfish’s liver and kidneys before it spreads externally. This makes it difficult to treat this disease in the early stages because most goldfish will not show symptoms until the disease has progressed.
Raised pale scales
White fluffy growths across the body
Slime trailing off the goldfish
Rapid breathing
Lethargy
White growths on the mouth
Raised pale scales
White fluffy growths across the body
Slime trailing off the goldfish
Rapid breathing
Lethargy
White growths on the mouth
Treatment: A salt bath or dip every couple of hours is recommended to treat mild cases of white fungus disease. It is important to keep the goldfish in a treatment tank isolated from other goldfish as this disease is highly contagious. For more severe cases, methylene blue baths or machalite green dips can be effective at killing off this fungus. Pimafix has proven to be an effective treatment against white fungus disease.
Prevention: Gradually lower the temperature in the aquarium and ensure that you do regular water changes to improve the quality of the water. Avoid handling your goldfish or placing dirty hands and equipment into the water column.
Symptoms:
Sluggish behavior
Loss of balance
Dull coloration
Loss of appetite
Weight loss
Hollow belly
Cysts
Treatment: It is difficult to treat this fungal disease in its advanced stages, but if you are lucky enough to treat your fish for this disease while the fungus is still internal, then there is a higher recovery rate. Your goldfish will need to be placed on the medication used to treat internal fungal and bacterial infections. The cysts and body sores can be treated using a salt bath. The medication can be introduced into your goldfish’s body by soaking it into their food.
Prevention: This fungal disease is difficult to prevent but ensuring that your goldfish are kept as stress-free as possible is important. Keep the water temperature lowered to prevent the spores from multiplying and avoid handling your goldfish’s food with dirty hands.
4. Ulceration Disease (Achlya)
Most commonly caused by poor water quality, ulceration disease is a fairly common fungoid that affects goldfish. This disease is highly contagious, and all the aquarium inhabitants should be treated even if you notice that only one fish is infected.
Sluggish behavior
Loss of balance
Dull coloration
Loss of appetite
Weight loss
Hollow belly
Cysts
Sluggish behavior
Loss of balance
Dull coloration
Loss of appetite
Weight loss
Hollow belly
Cysts
Treatment: It is difficult to treat this fungal disease in its advanced stages, but if you are lucky enough to treat your fish for this disease while the fungus is still internal, then there is a higher recovery rate. Your goldfish will need to be placed on the medication used to treat internal fungal and bacterial infections. The cysts and body sores can be treated using a salt bath. The medication can be introduced into your goldfish’s body by soaking it into their food.
Prevention: This fungal disease is difficult to prevent but ensuring that your goldfish are kept as stress-free as possible is important. Keep the water temperature lowered to prevent the spores from multiplying and avoid handling your goldfish’s food with dirty hands.
Symptoms:
White film over the eyes
Swollen gills
Respiratory distress
Lethargy
Slimy film covering the body
Treatment: If your goldfish is in the early stages of this disease, salt baths will help to kill off and prevent the fungal spores from multiplying. More advanced cases will require a stronger medication like malachite green or methylene blue dips to combat the damage this fungus can cause. You can also use medications with copper sulfate but be sure to follow the correct dosage on the bottle of the medication.
Prevention: Keep the goldfish aquarium clean and ensure that there is plenty of water movement from a filtration system. A warm and stagnant aquarium can be a breeding ground for this type of fungus. Regular water changes will also help to improve the quality of the water.
- See Also: Why is My Goldfish Swimming Erratically? Goldfish Behavior Explained
White film over the eyes
Swollen gills
Respiratory distress
Lethargy
Slimy film covering the body
White film over the eyes
Swollen gills
Respiratory distress
Lethargy
Slimy film covering the body
Treatment: If your goldfish is in the early stages of this disease, salt baths will help to kill off and prevent the fungal spores from multiplying. More advanced cases will require a stronger medication like malachite green or methylene blue dips to combat the damage this fungus can cause. You can also use medications with copper sulfate but be sure to follow the correct dosage on the bottle of the medication.
Prevention: Keep the goldfish aquarium clean and ensure that there is plenty of water movement from a filtration system. A warm and stagnant aquarium can be a breeding ground for this type of fungus. Regular water changes will also help to improve the quality of the water.
Conclusion
Fortunately, most goldfish fungal diseases are treatable. If you suspect that your goldfish might be suffering from a type of fungus, you must begin the correct treatment right away so that they have a better chance of recovery. By practicing good aquarium hygiene methods and keeping your goldfish stress-free, you will be able to help prevent the most common fungal diseases from affecting your goldfish.
Featured Image Credit: Hans Braxmeier, Pixabay
