Common Freshwater Fish Diseases

There are many types of fish diseases and the best way to prevent them is to prepare ahead of time. Here we explain the different types of diseases, including the many ways to prevent and treat your affected fish. Please read carefully, as your fish are live animals and require great care.

Cloudy Eye

Cloudy eye is a cloudy white film or grey haze that forms over the fish's eyes, giving an opaque appearance. In serious cases, fungal growth may also appear on the eyes. Treatment must be done immediately, as further infections may occur and lead to blindness.

Causes

  1. Poor water quality or harmful chemicals introduced into water
  2. Physical injury to the eye
  3. Accelerated production of slime due to irritation or poisoning
  4. Bacterial infections or physical markings on the fish

Prevention

  1. Maintain good water parameters and regularly clean tank. Remove uneaten food after feeding time, and conduct regular water changes.
  2. Choose compatible tank mates to minimize risk of fighting and physical wounds or other stress factors.
  3. Quarantine new fish before introducing to your aquarium and reduce the use of live feed to minimize risk of introduction of diseases or parasites.

Treatment

  1. Check water parameters and adjust accordingly to maintain healthy water.

Further Notes

  • During the course of medication, remove mediums such as activated carbon, and zeolite, as these mediums may reduce the effectiveness of medications.
  • Increase oxygenations with the introduction of an Air Pump during the medication period. After introducing the Air Pump, observe affected fish for any signs of distress or heavy breathing for the next two hours. If that appears so, immediately conduct a water change (50%). Ensure that the fresh water supply has been properly treated with tap water conditioner.

Dropsy

Dropsy (also know as Pinecone, Potruding Scales, or Edema) is caused by bacterial infection of the kidneys. This may be caused when the fish suffers physical injuries, diseases, poor water conditions, or mucosal damage.

The kidney is very important. When damaged, the fish is unable to regulate the body's water balance, which results in swelling. The swelling appears typically around the abdomen, causing the scales to portrude and give off a spiky, pinecone-like appearance.

Prevention

  1. Maintain good water parameters and regularly clean tank. Remove uneaten food after feeding time, and conduct regular water changes.
  2. Choose compatible tank mates to minimize risk of fighting and physical wounds or other stress factors.
  3. Quarantine new fish before introducing to your aquarium and reduce the use of live feed to minimize risk of introduction of diseases or parasites.

Treatment

  1. In the early stages of dropsy, add aquarium salt according to the recommended dosage. It is recommended to isolate the affected fish and any other fish that would cause further injuries. The water should be kept constant at around 30°C. Closely observe your fish and if you notice that the fish breathes and swims normally, do not add any new medication. Allow the fish to recover naturally.

Further Notes

  • During the course of medication, remove mediums such as activated carbon, and zeolite, as these mediums may reduce the effectiveness of medications.
  • Increase oxygenations with the introduction of an Air Pump during the medication period. After introducing the Air Pump, observe affected fish for any signs of distress or heavy breathing for the next two hours. If that appears so, immediately conduct a water change (50%). Ensure that the fresh water supply has been properly treated with tap water conditioner.

External Injuries

External injuries are common and may happen due to several factors. They may be injured while handling, hitting against rough surfaces in the aquarium, or by fighting with tankmates.

Prevention

  1. Minimize amount of handling and choose compatible tank mates
  2. Avoid large decorations with rough surfaces. Allow sufficient swimming space in your aquarium

Treatment

  1. Quarantine the injured fish for treatment

Further Notes

  • During the course of medication, remove mediums such as activated carbon, and zeolite, as these mediums may reduce the effectiveness of medications.
  • Increase oxygenations with the introduction of an Air Pump during the medication period. After introducing the Air Pump, observe affected fish for any signs of distress or heavy breathing for the next two hours. If that appears so, immediately conduct a water change (50%). Ensure that the fresh water supply has been properly treated with tap water conditioner.

External Ulceration

The main cause of external ulceration is due to bacterial infection. Low water quality or feeding unclean food will lead to fishes with weakened immunity due to bacterial infection to be affected.

This may also result from an infection from parasitic or physical wounds.

Prevention

  1. Maintain good water parameters and regularly clean tank. Remove uneaten food after feeding time, and conduct regular water changes.
  2. Choose compatible tank mates to minimize risk of fighting and physical wounds or other stress factors.
  3. Quarantine new fish before introducing to your aquarium and reduce the use of live feed to minimize risk of introduction of diseases or parasites.

Treatment

  1. Dose Yellow Powder according to the recommended dosage. 
  2. Continue treatment and perform a 30% water change every 3 days.

Further Notes

  • During the course of medication, remove mediums such as activated carbon, and zeolite, as these mediums may reduce the effectiveness of medications.
  • Increase oxygenations with the introduction of an Air Pump during the medication period. After introducing the Air Pump, observe affected fish for any signs of distress or heavy breathing for the next two hours. If that appears so, immediately conduct a water change (50%). Ensure that the fresh water supply has been properly treated with tap water conditioner.

Fish Lice

 

Prevention

Treatment

Further Notes

More coming soon...

Gill Rot/Gill Infection

 

Prevention

Treatment

Further Notes

More coming soon...

Mycosis/Fungal Infection

Prevention

Treatment

Further Notes

More coming soon...

Swim Bladder Disease

Prevention

Treatment

Further Notes

More coming soon...

White Spot/Ich

Prevention

Treatment

Further Notes

More coming soon...

Velvet/Rust-Gold Disease

Prevention

Treatment

Further Notes

More coming soon...

Fin Rot

Prevention

Treatment

Further Notes

More coming soon...

Gill Flukes

Prevention

Treatment

Further Notes

More coming soon...

External Ulceration

Prevention

Treatment

Further Notes

More coming soon...

 

Useful Links

Medications:

https://www.missaquarium.ca/collections/medication

 

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