Guppy Diseases, Parasites, and Remedies: Here’s Everything You Need to Know!

Like any animal, guppies are not spared from any disease or parasite. They are susceptible to all forms of harm. The best thing about this is that remedies are easily available.

So, in this article, we will try to learn more about guppy diseases, parasites, and remedies. After all, it is vital that you know how to take care of your pets!

Prevention is better than cure! To make sure that your guppies do not suffer, you need to observe the following:

  • Conduct partial water changes at least once a week;
  • Feed them properly;
  • Inspect them every day, visually;
  • Maintain water parameters and temperature at the right levels;
  • Quarantine new fish in a separate tank for three to four weeks before introducing to the main tank;
  • Remove dead fish from the main tank right away;
  • Relocate sick fish in a separate tank

Stress is the most common cause of diseases among guppies. It affects their immune system, making them physically more vulnerable.

It goes without saying that one of the best ways to prevent guppy diseases is reducing stress levels. To do this, you need to address the factors causing stress.

You can start by adding more live aquarium plants in the main tank. This will provide your guppies with ample hiding spots.

It is also important to remember that overcrowding could be a problem for guppies. You have to limit their number in a particular tank. More importantly, do not place them in the same tank as aggressive fish.

Using a heater will help keep temperature at proper levels. Keep in mind that too low or too high temperature can lead to stress.

Maintaining water quality is also crucial. You need to conduct partial water changes at least once a week. The fresh water in your main tank should always be free of chlorine and have the correct pH level and temperature.

Common Guppy Diseases, Parasites, and Remedies

Even if you do your best to prevent your guppies from suffering, it is still important to know what are the common diseases that can affect them. This will help you provide the best remedies as soon as you notice signs of such diseases.

1.Bent Spine/Crooked Back/Scoliosis

Even guppies may suffer from Bent Spine. In fact, it is prevalent among young ones. Usually, it is caused by environmental factors and genetics. In-breeding is one of the leading causes, particularly affecting female guppies.

In some cases, it can be observed on the sides. There are also cases where it can be observed from above.

Those who suffer from this disease have slow growth and trouble swimming. Generally, they are weaker and have a short lifespan.

While they are allowed to reproduce, it is not highly recommended. The disease can be passed genetically; and there are high chances of the offsprings inheriting it.

There is no cure for this condition. It is also not contagious but is hereditary. The best thing you can do is to make sure that they live the best possible life they could. You can start by providing them with a consistently healthy diet and environment.

2.Camallanus Internal Worm

Camallanus is one of the most common parasites affecting guppies. It sticks out from their anuses, growing up to 0.8” long. You can easily tell it apart from waste because of its brown or orange color. Also, it moves like a worm.

There are no evidences of its origins. However, it usually occurs among guppies living in outdoor ponds. Feeding guppies with Cyclops may also cause the parasite to develop. So, preventive measures include minimizing your guppies’ Cyclops consumption.

To treat this parasite, you may apply Levamisole or Ergamisol for at least five days. Other great alternatives include Fenbendazole and Parcide X or D.

Then, make sure that you vacuum the substrate and clean the filter completely. Lastly, perform big partial water change of 70% to 90%. After three weeks, you have to repeat the whole process.

3.Columnaris and Mouth Fungus

Columnaris and Mouth Fungus may look like fungal infection but in reality, the main cause is bacteria. It starts as bacteria colony forms around your guppies’ mouths or their bodies’ middle areas.

When affected with this disease, your guppies will have a hard time swimming. The bacterial infection has that paralyzing effect to the muscles. Aside from swimming difficulties, they may also lose their appetites as a symptom.

The bacterial infection is highly contagious and easily affects female guppies. In fact, it can wipe out your entire fish colony!

So, it is important to take the necessary steps as soon as you notice the symptoms. You may use Formalin or Maracyn; but aquarium salt is also a great alternative.

When using aquarium salt as a remedy, perform a 50% partial water change first. Then, add a teaspoon of aquarium salt per gallon of water. Do this once a day for three consecutive days.

Let the aquarium salt stay in the tank until your guppies are completely healed. Then, perform 50% to 70% partial water change.

Another remedy is a 30-minute potassium permanganate bath. However, extra care must be observed when using this remedy. Potassium permanganate is a strong oxidizing agent; so, do not exceed 10 mg/l for a bath. Otherwise, it will burn your guppies, doing more harm than good.

The good news is that, you can prevent this disease. There are just three key preventive measures you should observe:

●   Avoid overcrowding;
●   Ensure proper filtration; and
●   Perform partial water changes regularly


Dropsy is a bacterial infection with the most noticeable symptoms being discoloration and swelling. Sometimes, you will also notice distortion. Your guppies’ scales elevate from their bodies, effectively looking like spine cones.

Usually, this disease is caused by too much bloodworm consumption and/or severe stress. It is the internal organs of your guppies that are affected; so, there is really no remedy. By the time you notice the symptoms, the damage is already severe— there is no going back.

So, what can you do? The best thing you can do is prevention. Make sure that the tank they live in has excellent water quality all the time. Since eating too much bloodworms is likely a cause as well, you should consider providing a wide variety of fish food.

5.Gill Flukes

Gill Flukes is caused by tiny white worms. You can easily spot these because of their characteristics.

Your guppies will gasp for air constantly at water surface. In some cases, they will just sit at the bottom of the tank as they find trouble in breathing.

This disease can be fatal. Once their gills bleed, there is nothing you can do to save them.

In its early stages, however, it is still possible to treat them. Apply special medication in the whole tank where they got sick. Make sure that you follow the instructions in the label.

These worms come from new fishes and plants. So, to prevent them from hurting your guppies, it is best that you quarantine new fishes and plants before introducing them in your main tank.

Additionally, always maintain excellent water quality. Poor water quality is a contributing factor to the spreading of gill flukes.

6.Guppy Disease/Protozoan

Protozoan is a tiny parasite that commonly affects guppies, causing guppy disease. While it may affect other fish breeds, guppies are the most susceptible to its harmful effects.

The parasite attaches to their skin, slowly penetrating their bodies through the muscles. Eventually, it reaches their bloodstreams.

Usually, this disease develops when the tank is unheated or has poor water quality. So, to cure it, make sure that the tank has a heater that maintains water temperature at the proper levels.

In its early stages, it can be treated using Formalin or Malachite Green. In its late stages, you will need copper medication such as Seachem Cupramine. Once your guppies are healed completely, it is necessary that you perform 50% to 70% partial water change.

7.Ich/White Spots

Ich or white spots is a bacterial infection that you can easily detect. One of the common symptoms you will notice is skin rubbing against decorations, plants, rocks, and anything else in the tank. Your guppies may also lose their appetites as a sign.

Other visible signs, of course, include small white spots. You will notice these on their skin and/or fins.

It should be treated right away in order to prevent fatality. Here is how you can treat ich:

●    Slowly increase the tank’s water temperature to 80°F.
●  Add a teaspoon of aquarium salt per gallon of water. You may also use other recommended medications. Just make sure that you follow the proper dosage.
●    Maintain this stage for four days to a week.
●   Then, slowly decrease the tank’s water temperature back to normal.
●  Siphon as much of the substrate as possible by doing as much as 70% partial water change.

Note that it is ideal to treat your sick guppies in a hospital tank. However, it is also required to apply aquarium salt or medication in the tank where they got sick.


Oodinium or velvet is almost similar to ick. The only difference is that with this disease, your guppies’ bodies become covered with tiny gold dots. In fact, they actually look like gold dust!

However, it is difficult to notice, especially in its early stages. You will only see it once their skin starts to peel off and they bleed.

While it rarely occurs among hobby pet guppies, it is extremely contagious. It easily spreads to all fishes in a tank.

If, by any chance of luck, you notice the signs early, you may use copper medication. Be mindful that this is deadly to shrimps and snails. So, see to it that there are no shrimps and snails in any tank where you will apply copper medication. Similarly, you cannot place shrimps and snails in a tank where it has been applied.

It is highly recommended that you turn off the lights in the tank during the entire treatment process. Accordingly, doing so will deliver the best results. Lastly, make sure that you perform 50% to 70% partial water changes once your guppies have healed completely.

9.Popped Eyes

There are a lot of factors causing popped eyes, making it hard to cure. Some of the most common causes include the following:

●   Bacterial infection;
●   Dropsy fungus;
●   Internal parasites;
●   Poor water quality; and
●   Tuberculosis;

While it may not be fatal, it could be blinding. Since there are a lot of possible causes, you may experiment with various remedies. However, that is not highly recommended because it may only do more harm than good.

10.Rotting Fins and Tail

Rotting fins and tail could either be bacterial or fungal infections. A clear sign of this disease are the fins and tail looking like they are stuck together.

Usually, it is caused by ammonia burns and poor water quality. It is important that you know the primary cause to know the proper treatment.

You will know that it is a bacterial infection if there is no damage but there is an obvious rotting. On the other hand, you will know that it is a fungal infection if there is both damage and rotting.

To cure your guppies from this disease, you need to transfer them into a hospital tank. If it is caused by bacteria, you can use antibiotics such as Maracyn, Maracyn 2, Seachem ParaGuard, Tetracycline, among others. If it is caused by fungi, you need to apply special medications. Then, if it is related to ammonia burns, make sure that you improve the water quality of the tank.

11.Swim Bladder Disorder

Swim bladder is one of the most important fish organs because it helps control buoyancy. Filled with gas, it helps fishes maintain balance while swimming.

Usually, severe stress causes this disease. Particularly, it is the stress arising from moving them from shallow to deep water levels.

Clear signs include the inability to swim properly— failure to control and maintain balance. It is caused by poor water quality or high levels of ammonia.

So, the best way to prevent and even cure it is to maintain high water quality all the time. You can do this by performing regular partial water changes.

12.Swim Bladder Inflammation

Swim Bladder Inflammation is one of the diseases easiest to detect. Your guppies’ bellies will look distend. It is also weird because it will make them swim with their heads pointing to the substrate.

The bad news is that there is no treatment available because it is caused by a virus. If you notice the said symptoms, remove the affected guppies from the tank right away. Unfortunately, death is the only way out of this disease.

13.Swollen Gills

Gills are important for breathing. Fishes take water in through their mouth and release it through their gills. Rake, which is the fish equivalent for lungs, is used to take out oxygen from water. Needless to say, it plays a very crucial role and is sensitive.

Ammonia and carbonate poisonings are the usual cause of this disease. Ammonia is a very dangerous toxin resulting from decomposed food, fish waste, and other organic matter.

In low quantities, it can burn gills and inflate them. In high quantities, it can cause death. Meanwhile, carbonate is present in different rock formations and substrate.

When your guppies gasp for air at water surface, it might be a sign of swollen gills. If you notice rapid gill movement as they do, perform a 50% partial water change immediately.

Over the next couple of days, closely monitor water parameters. Test for ammonia if possible. You may also apply a nitrifying bacteria in the tank.

It is also important that you stop feeding them during the healing process. This helps prevent ammonia spikes.


Tuberculosis is an alarming disease caused by mycobacterium. First, your guppies will lose their appetites. Next thing you know, they have rotting fins and tails, skin discolorations, and ulcers on their bodies. Then, they become inactive and die a slow death.

There is no treatment for this disease. It can also be passed genetically. It is not contagious, but others can get affected if they happen to consume the body of a guppy that died of tuberculosis.

Make sure that you quarantine guppies as soon as they exhibit any symptom. You would not want the affected fishes to spread it to others. If there are no improvements after a few days in a hospital tank, destroy them to prevent it from spreading.

When affected guppies die, remove them from the tank immediately. You would not want others to get infected through ingestion.

Keep in mind that it may be passed to humans as well. So, it is really important that you deal with it extra carefully.

15.Viral Hemorrhagic Septicaemia (VHS)

VHS is a dangerous disease caused by viruses within your guppies’ blood. In its early stages, it exhibits lesions as symptoms. Then, sores and ulcer will develop. Their fins will start to rot. Eventually, they will lose their appetites and stop eating. Other possible symptoms include bulging eyes, pale gills, and skin color darkening.

The best remedy for this disease is Maracyn 2. Performing big partial water changes post-treatment is also necessary.

Guppy Diseases, Parasites, and Remedies: To Wrap It Up…

There is really a lot to learn about guppy diseases, parasites, and remedies. Even if you are confident about the health of your guppies, it is vital that you know all these information.

Like what they always say, prevention is better than cure. And what better way to prevent diseases than to understand their causes, right?

There are a lot of diseases that can affect your guppies. Some are even fatal, which means that there are no possible remedies to save your pet fishes.

Always be mindful of your guppies’ overall condition. Sometimes, symptoms do not show until everything is too late. Make sure that you perform regular partial water changes to maintain a healthy environment for them.

More importantly, feed them a healthy diet of wide variety.

Do you have an experience taking care of sick guppies? How did you deal with it? Did they get better or worse? What remedies did you apply? What else can you recommend to your fellow readers? Feel free to share your thoughts!

Jennifer Wood

Hi there, my name is Jennifer Wood, founder of - a great resource for pets lovers.

Click Here to Leave a Comment Below 0 comments