Hole In The Head Disease in Betta Fish: Symptoms, Treatment, Prevention

betta hole in head disease
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If you notice holes in the head of your betta fish, they might suffer from the hole-in-the-head disease.

Although it is normally more common in cichlids, betta fish are not immune to the hole-in-the-head condition as they can catch it at any stage of their lifecycle.

In fact, I had both angel fish (a cichlid) and my betta fish with the hole-in-the-head disease when I was much younger – perhaps at 10 years old.

The good news is that this condition is treatable and preventable.

So, if you notice that your bettas are suffering from hole-in-the-head disease, there’s nothing to panic about.

With the proper knowledge about the causes and symptoms of the hole-in-the-head condition, you can keep your bettas safe from this severe condition.

This guide will explain causes, symptoms, treatments, and preventative measures in detail so you can act better for the well-being of your bettas!

What is hole-in-the-head disease?

The hole-in-the-head is a common disease among freshwater fish species. It’s also called freshwater head or lateral line erosion.

Many aquarists use the term “hexamitiasis” for hole-in-the-head disease. Many expert aquarists believe that hole-in-the-head disease is a parasitic infection.

They think that holes in the head and the body of betta appear due to flesh-eating by the parasite.

However, there’s no scientific evidence available to support this theory.

What causes hole-in-the-head disease in betta fish?

While the exact cause of hole-in-the-head is unknown, aquarists believe that the following factors can show up to be the causes of this disease:

Malnutrition (Lack of essential vitamins)

Malnutrition can trigger hole-in-the-head conditions in your betta fish by weakening their immune system, especially when they’re not getting the essential vitamins (Vitamin A & Vitamin C) in the required amount.

Betta fish are mainly carnivores, so getting essential vitamins is difficult for them.

Therefore, feeding your bettas a high-quality, vitamin-rich diet is recommended to prevent malnutrition in them.


Experts aquarists believe that a bacterium called “Hexamita” can cause the hole-in-the-head disease in betta fish, explaining why the term “hexamitiasis” is used to refer to this disease.

It’s a parasitic bacterium that spends most of its lifecycle in the intestines of freshwater fish.

Normally, Hexamita doesn’t cause any harm to your bettas, but when their immune systems weaken, it starts infecting their organs.

In severe cases, the infection spreads so much that it affects the sensory pores on your betta’s head.

When the immune system responds to fight off the infection, the affected sensory pores fill with pus and eventually burst, leaving holes in the head.

Poor water conditions

Poor water conditions increase the risk of your betta suffering from the hole-in-the-head disease.

If you leave your betta fish in poor water conditions for long periods of time, they might even become susceptible to other illnesses besides hole-in-the-head.

Food leftovers, bioload from fish, excessive debris in the bottom of the aquarium, and overcrowding contribute to poor water quality for your betta fish.


Stress is directly linked to the weakening of the immune system in betta fish.

Suppose your bettas have become stressed out due to poor water conditions, low-quality diet, aggression from other tankmates, or overcrowding.

In that case, their immune system may lose the capacity to fight off parasites like Hexamita and become prone to the hole-in-the-head disease.

Therefore, it’s necessary for you to avoid your bettas from becoming stressed out.

Sudden changes in aquarium parameters

Besides poor water conditions, introducing sudden changes in aquarium parameters can lead to the weakening of the immune system in your bettas.

For example, a sudden rise or fall in the temperature or the pH of your aquarium water may leave your betta fish shocked or stressed out in severe cases.

In fact, an intense fluctuation in the aquarium water’s pH may threaten your betta’s life.

Therefore, maintaining the aquarium parameters at an optimum level and keeping it stable is extremely important for the health and well-being of your betta fish.

Signs and symptoms of holes in the head disease in bettas

A hole in the head

The most noticeable symptom of the hole-in-the-head condition in betta fish is obviously holes in their head skin.

From my experience, you’ll see a dark circular spot on the head of your fish.

After a few days, you’ll notice that the hole has developed, and you can see the flesh of your betta fish.

And in a few more days, the hole passes through the flesh, and you can see inside the head of your fish.

This is the closest picture I can find that looked similar:

Angelfish with Hole In The Head Disease
Credits: https://forum.aquariumcoop.com/topic/13172-angelfish-disease-should-i-euthanize/

It will look as if the bacteria have eaten through the head of your betta – straight out of a zombie movie.

The holes may also appear in body areas other than the head.

However, there’re various other symptoms that betta fish may develop, such as:

Loss of colouration

Affected betta fish lose their body colouration. and is an easily noticeable symptom for anything wrong in bettas.

Healthy bettas are attractively colourful, but their colouration starts to fade when they suffer from the hole-in-the-head condition.

However, it’s not a clearcut indication of hole-in-the-head disease in betta fish because it can also result from many other conditions such as stress and depression.

Stringy white poop

If your betta’s faeces is white with a stringy look, it might be a symptom of hole-in-the-head.

As mentioned earlier, the Hexamita bacteria live in the intestines of betta fish.

So, when they start spreading, the intestine of betta produces a white mucous to fight off the infection.

A considerable amount of this white mucous also comes out in the faeces, giving it a white colour and stringy appearance.

Anorexia (loss of appetite) and weakness

As the hole-in-the-head condition spreads from the intestine, your betta may start experiencing a decrease or complete loss of appetite.

The affected betta fish may also develop weakening in their body as a manifestation of losing appetite. In this situation, your betta stops eating for a certain time.

It happens when the infection gets severe and begins to reach its last stages.

Immediate action is required if you notice a loss of appetite in your betta fish.

However, loss of appetite is not specific to holes in the head; several other illnesses, including swim bladder disease, dropsy, and constipation, can also cause it.

Therefore, you should always look for other symptoms before deciding whether your bettas suffer from the hole-in-the-head disease.

Hole-in-the-head is rarely fatal, so the chances of your betta’s recovery are always good.

However, if the condition is left untreated, the holes may get deep and become life-threatening for your betta.

In other words, hole in the head disease can be fatal if untreated – and my angels and betta fish were victims of my lack of knowledge back them.

That’s why you should immediately start the treatment procedure after diagnosing the condition.

How to treat hole-in-the-head disease in bettas?

Various treatment methods can be applied to cure the hole in the head disease in your betta fish, but the effectiveness of the treatment depends on the severity of the condition.

For example, if you’re treating the hole in the head condition in its last stage, the chances of your betta’s recovery are slim because the treatment is less likely to be effective.

The severe or last stage of the hole-in-the-head disease is described by deep holes in your betta’s head and other body parts.

And when I mean deep, it’s really deep and scary to see such a disease exists.

On the other hand, your betta fish can fully recover from the illness if the treatment is initiated in the early stage of infection.

Medication or drug therapy is believed to be the most effective treatment for hole-in-the-head disease among all available treatments.

Medication or drug therapy

A variety of medications is available in pet stores that can be used to treat hole in the head disease in betta fish.

Dimetridazole and metronidazole are some reputed examples of such medications.

You can use any recommended medication available at pet stores, but it’s essential to consult your vet first.

Your vet can help you determine the right medication dosage for the hole-in-the-head disease.

Once you get the right medication and determine the optimum dosage, it’s time to administer it.

You can medicate your bettas for the hole in the head disease in two ways:

Adding medication to the food

Medicating your betta fish through food is easier than treating them by adding medication to the aquarium water.

However, this method is only applicable when your bettas are still eating, something only possible in the early stage of infection.

At the severe stage of the hole-in-the-head disease, bettas may stop eating, so you cannot medicate them through food.

Adding medication to the food is also preferred because adding medication to the aquarium water can affect live plants, bacteria colonies, and healthy fish.

So, if your betta is not experiencing loss of appetite, adding medication to food should be your first choice.

Adding medication to water

If your bettas are no longer eating, you must rely on bathing to medicate them. You can follow these tips:

  • Prepare a quarantine tank. Take a clean container for this purpose and fill it with aquarium water.
  • Dissolve the recommended dosage of the medication in the quarantine tank. The amount can be changed according to the severity of the disease by consulting with your vet.
  • Leave it for some time so the medication can spread everywhere in the tank.
  • Shift your bettas from the main aquarium to the quarantine tank to medicate them. Depending on your vet’s or the medicine manufacturer’s instructions, you can leave them in the quarantine tank for 5-10 minutes.

How to prevent hole-in-the-head disease in bettas?

It’s challenging to figure out the exact cause of the hole-in-the-head disease in betta fish, but you can take several preventative measures to prevent the condition from happening in the first place, such as:

Give your bettas a vitamin-rich diet

The diet should contain all essential vitamins for your betta’s normal growth and health.

It must also contain all essential nutrients recommended by your vet.

If you can prepare a balanced diet for your betta by yourself, you can purchase a ready-made diet from reputable pet stores in your area.

I like Dr Bassleer’s BioFish Food with Garlic.

It’s also important that your betta fish must eat live foods, as they’re a rich source of vitamins, nutrients, and minerals.

Here’s my guide on how to feed betta fish.

Maintain high-quality water conditions in the aquarium

Keep the aquarium clean and well-maintained to prevent your betta fish from becoming stressed.

The aquarium shouldn’t have food leftovers, debris, bioload, and high levels of ammonia.

You can use a heavy-duty filtration system to ensure the cleanliness of your water tank.

You should also constantly test your water conditions to make sure everything’s alright.

Avoid overcrowding in your aquarium

Overcrowding cannot only pose a physical threat to your betta fish, but it can increase the levels of ammonia in the water – which is deadly.

If your tank is not large enough to accommodate all your fish, you should consider upgrading to a larger tank.


The hole-in-the-head disease is not a common illness in betta fish, but it’s definitely possible for your bettas to be susceptible to it.

It can result from Hexamita bacteria, poor water conditions, stress, and a low-quality diet.

Hole-in-the-head can be diagnosed by noticing its symptoms, including holes in the head, whitening of faeces, and loss of body colouration.

Although this condition rarely proves fatal, prevention is always better than treatment.

Following the above-mentioned preventative tips can help keep your betta safe from the hole in the head disease.

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