Neon Tetra Disease In Cardinal Tetras| How Fast Does This Disease Kill Your Fish?

It is certainly a well-known fact that diseases are constantly degrading the life of your beautiful animal in your aquarium. Whether it may be lack of proper tank setup, genetic, polluted environment, or fighting among aquarium animals. Fishkeepers do complain about the various disease. Among those, neon tetra disease has become a serious threat for fishes like Cardinal tetras.

Neon tetra disease will usually take about 14 to 60 days to kill your Cardinal tetras. Neon tetra disease is contagious and passes on from one fish to another fish. In the case of Cardinal tetras with suppressed immune systems, the time of death will be even shorter. Neon tetra disease is not so common but a fatal one that is difficult to cure after its onset.

It’s important to know the risks and how to keep your tetras healthy. So, we will explore the symptoms, transmission, and treatment of this illness in more detail below.

What Is Neon Tetra Disease?

Neon tetra disease is a disease that can affect neon tetras as well as cardinal tetras. It occurs due to the parasite erythrocytic inclusion bodies of Pleistophora hyphessobryconis. Contractions of this disease might be from eating an infected fish or if someone with contaminated hands feeds the tank without washing.

There is no solid cure for Neon Tetra Disease. The only way to prevent it is by keeping your tank clean and free of parasites, even dead fish.

What Is The Symptom Of Neon Tetra Disease In Cardinal Tetras?

Cardinal tetras only show subtle signs of illness when they suffer from Neon tetra diseases. But the signs might be more degenerative than they appear to be. This is why the cardinal tetras might die suddenly and unexpectedly, even if their water quality appears excellent.

The common symptoms that you need to look for are:

Loss Of Coloration:

The cardinal tetras will lose their bright colors and will appear to be pale in comparison.

Loss Of Appetite:

Even though they seem to lack appetite, the cardinal tetra’s metabolism is still active. They might try to eat, but because of this disease, their digestive system deteriorates beyond repair. This means that they might expel undigested food.

Sunken Fins:

The cardinal tetra’s fins will appear to be sagging or sinking inwards towards the fish’s body. This means these fishes are literally wasting away because of this disease.

Scoliosis Or Curvature Of The Spine:

This might be the most common sign of Neon Tetra Disease in cardinal tetras. This is because this disease causes scoliosis or curvature of the spine, which results in twisted spines and tails for these fishes.

Lethargy And Slow Movement:

Cardinal tetras are active fish, but they might become too lethargic and slow in their movement because of this disease.

Difficulty Breathing:

The cardinal tetras’ gill filaments will turn red and swell with this disease, which means their gills have a severe infection. As a result, Cardinal tetras might start to exhibit difficulty in breathing.

What Can You Do To Treat Neon Tetra Disease In Cardinal Tetras?

As soon as you notice the cardinal tetras showing any of these signs, it is best to take immediate action.

Change The Water

You first need to change about 25% of its water with fresh and dechlorinated water for at least 24 hours. This will help diminish the toxin levels in their body because of this disease.

Increase The Temperature

After water changes, try to increase the temperature of your aquarium water by two degrees Celsius for about four days and then return it to its normal temperature afterward. This is one way to slow down or stop the progression of Neon Tetra Disease in cardinal tetras because higher temperatures will not only reduce toxin levels but also reduce the strength of this disease.

Use Supplements In Diet

It is also best to supplement their diet with vitamin-enriched foods that will help increase your cardinal tetra’s immunity against Neon Tetra Disease. The most common way to do this is by adding food soaked in liquid vitamins directly into the tank, providing them live feeder fish soaked in liquid vitamins, or adding vitamin enriched flakes to their regular diet.

Use Medications And Antibiotics

Some medications are effective in treating Neon tetra disease, including methylene blue and acriflavine with erythromycin lactobionate. You can either use these medicines separately or together, depending on the symptoms exhibited by your cardinal tetras.

And finally, the last thing you can do to save your cardinal tetras from Neon tetra disease is by getting a broad-spectrum antibiotic treatment. This means that you need to treat them for bacterial infections and internal parasites, and fungal infections because these diseases often occur with this illness.

However, if your cardinal tetras are still not showing any signs of improvement even after administering the suggested treatments mentioned above, it is best to bring them to a fish veterinarian immediately for further examination and diagnosis.

How Fast Does Neon Tetra Disease Kill Your Cardinal Tetras?

Cardinal tetras are among the most popular fish in freshwater aquariums. But, unfortunately, they’re also one of the more sensitive varieties of tetras, making it crucial to keep a close eye on their health and well-being.

There is certainly no fixed time for the length of time it takes for a cardinal tetra fish to die from neon tetra disease. Most commonly, the fish will die in about 14 to 60 days after contracting the disease. However, this may last up to a couple of weeks, with no recovery at all in some cases. Or, Cardinal tetras with the weaker immune system might be able to live a little less.

But through proper care and a healthy environment, cardinal tetras can increase their chances of beating neon tetra disease.

What Are The Causes Of Neon Tetra Disease In Cardinal Tetras?

Neon tetra disease is an infection that occurs due to a parasitic infestation of the body. It can affect fish of all types, but it is most common in cardinal tetras and neon tetras because they are freshwater fish that live in South America.

The disease occurs due to a protozoan parasite called Pleistophora hyphessobryconis, which infects the fishes’ digestive tract causing damage throughout multiple organ systems. Sometimes the fish ingest different parasites when they eat food contaminated with feces.

Moreover, the common causes of Neon tetra disease in Cardinal tetras are:

Improper Water Conditions

The main causes of Neon tetra disease in Cardinal tetras is the poor condition and quality of the aquarium or tank environment. This includes harmful chemicals, parasites, toxins, bacteria, and other pathogens that can adversely affect aquatic life, causing diseases like neon tetra disease.


Another common cause of Neon tetra disease in Cardinal tetras is stress. When fish feel stressed, their immune system becomes weak. Thus, this makes them more vulnerable to diseases such as neon tetra disease.

Improper Diet

Another common cause of Neon tetra disease in Cardinal Tetras is the improper diet they consume. If you do not feed your cardinal fishes with the right kind of food, they can die due to malnutrition. This is one of the common causes of Neon tetra disease in Cardinal Tetras and other fish species.


Fish can also get injuries during fights with their own or any other species. In some cases, fish suffer from injuries due to sharp objects and gravels in the aquarium. Failure to treat these injuries properly leads to infections and diseases such as neon tetra disease.


Neon tetra disease can also affect the breeding process of cardinal fishes. If you fail to conduct the breeding process properly, it can cause neon tetra disease.


Genetics is another common cause of Neon tetra disease in Cardinal Tetras. The species tend to have a weak immune system because they are not genetically strong enough, making them more prone to neon tetra disease.

This may be one of the reasons why neon tetra disease is more common in certain types of fish species such as cardinals and neons only.

What Are The Fishes That Suffers From Neon Tetra Disease?

Neon tetra disease is more common among freshwater fishes.

The fishes that are more likely to get Neon tetra disease are:

  • Neon tetras
  • Cardinal tetras
  • Danios
  • Angelfish
  • Barbs
  • Corydoras catfish.


In conclusion, Neon tetra disease is a widespread and deadly fish illness. But this disease may not be the same in all cases since it will depend on several factors.

Moreover, Neon tetra disease is a complicated health issue with minimum chances of cure. Therefore, the best way to prevent it from spreading is by quarantining the sick fish and treating the disease thoroughly with specific medicines.

Hopefully, this blog post helped me understand more about Neon tetra disease in Cardinal tetras. For more information, feel free to contact us.

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