In general, betta fish suffer from several health conditions. However, the good news for keepers of this fish is that they can prevent or treat these health problems. Thus, if the infections occur in the aquarium, they can be identified and treated.

Ordinarily, you can categorize betta fish diseases and illnesses as fungal, parasitic, or bacterial. Particularly, most fungal infections result from previous health conditions. Also, parasitic ailments are the most contagious. Hence, it can be introduced into the aquarium by new fish. However, the most common causes of bacterial sicknesses include poor quality water and inappropriate fish handling methods.


  • signs that Your Betta has Fallen Ill
  • bacterial septicemia / red streaks
  • constipation among betta fish
  • columnaris
  • dropsy
  • betta fish fin/tail rot
  • fish lice in betta fish
  • fungus in betta fish
  • betta fish gill parasites
  • ich/white spots
  • betta fish intestinal parasites
  • popeye
  • poisoning
  • betta fish slime disease
  • betta fish swim bladder disorder

Signs that Your Betta has Fallen Ill

Although some of the following signs and symptoms may not always mean that your betta fish is ill. Particularly, many of these are telltale signs that your fish is ill. Generally, these symptoms cover most Betta fish illnesses.

Also, each specific illness will have its own unique set of signs and symptoms. These include

  • Damaged or abnormal fins
  • Color change (a sick Betta fish’s normal color may fade)
  • Also, disinterest in food for many days
  • Inactive or less active than usual
  • The tendency to remain at the bottom of the tank or oppositely gasping for air at the top of the tank
  • Likewise, spots that appear around your Betta’s head and mouth
  • Intermittent rubbing of fins along the side of the tank
  • Also, swelling of Betta
  • Enlarged eyes
  • Pale yellow puss
  • Lastly, difficulty swimming

Bettas Diseases and Treatment

In general, it is important to examine and determine your Betta’s illness and treat it as soon as possible. Particularly, it is because often it will decide the fate of your fish.

Thus, each section below has an explanation on

  • the cause,
  • symptoms and
  • also, treatment.

Bacterial Septicemia / Red Streaks

Generally, it is one of the less likely Betta fish illnesses caused by Streptococcus.


In particular, Pseudomonas or Streptococcus causes bacterial septicemia.


Particularly, bloody red streaks that occur across the body and fins, which are

  • bloated,
  • gasping for air,
  • ulcers,
  • lethargic and
  • loss of appetite.


Usually, a trained veterinarian who will medicate your Betta with an antibiotic in a quarantined tank can best handle this case.


Generally, it is commonly due to their high protein diet with little fiber.

Meanwhile, it is important to treat it very early to avoid more serious problems with your Betta.


Ordinarily, feeding your Betta too much food or the wrong type of food can cause constipation. Also, dried foods can lead to constipation as they swell inside the stomach.

In contrast, live frozen food which your betta can digest easily without any problem is different.


  • first, swollen stomach,
  • feces remain attached or oppositely,
  • also, the inability to pass feces,
  • lastly, disinterest in food and inactivity


By and large, if your betta is showing any of the symptoms, then you should do the following:

  • Particularly, fast your fish for up to three days to allow all feces to pass and then introduce live foods.
  • However, if unsuccessful, you can give your Betta a small amount of daphnia. This helps to reduce constipation. Meanwhile, others recommend feeding them the tiniest piece of a cooked pea.
  • Thus, once your fish is passing feces normally again. Next, it is important to cut down on the amount of food you were feeding him previously. Particularly, as this is a large contributing factor to Betta constipation.

Columnaris / Mouth Fungus

Columnaris often called mouth fungus is a common bacterial infection.

Particularly, it affects fish that fall for another illness or stress, such as a poor diet or unsatisfactory environment. Thus, to prevent this disease, maintain high-quality water and disinfect all equipment before it enters the tank.

Specifically, columnaris is highly contagious. Thus, it is vital you remove and incubate infected Betta fish.

Generally, this disease can be internal but more common externally on Betta fish. Likewise, there is a slow and fast strain of this infection. Hence, it depends on which one your Betta has. Thus, it will determine how likely it is to overcome the illness.


In general, Saprolegnia species cause this illness.


Particularly, this is a cotton-like growth around Betta’s mouth and white spots on mouth and fins. Meanwhile, as this infection spreads, the Betta’s fins will become frayed.

However, if the infection is internal, it can often show no symptoms at all. As a result, making it hard to diagnose before it is too late.


Thus, to ensure that you treat Columnaris you must first clean the bacterial infection from the entire tank. In particular, this includes:

  • changing the water,
  • vacuuming the gravel and
  • adding aquarium salt.

Meanwhile, once you are through with cleaning the tank, you can treat with an antibiotic or copper sulfate.


Generally, dropsy is a rare disease and is fatal. Thus, if contracted, it leads to kidney failure. Therefore, it is important to know the signs and symptoms to ensure you isolate the fish you believe to have this disease to keep other Bettas safe.


Usually, multiple sources cause this illness. Specifically, you can trace it to when bacteria get into the tissue of the fish resulting in organ failure.

Also, fluid retention within the fish causes the noticeable bloating of this disease. Similarly,

  • poor water quality,
  • stress when transporting,
  • lack of nutrition,
  • drop in water temperature and
  • other aggressive fish contribute to ones Betta contracting this disease.


Particularly, here are the common symptoms

  • bulging eyes,
  • feces become pale and string-like,
  • also, protruding scales are noticeable when viewing fish from above,
  • swollen body,
  • Lastly, Betta fish becomes inactive and disinterested in food.


Unfortunately, once the disease progresses, there is no reliable treatment for your Betta fish. Hence, it is best that you euthanize your fish so that it does not suffer further from this disease.

Fin / Tail Rot

Generally, this is common in Betta fish and starts at the end of the fin and works its way towards the body in more progressive stages. Meanwhile, if you treat it, the recovery rate is high. However, when fins and tails grow back they may not be as vibrant or long as they previously were.


Specifically, two Bettas fighting can cause fin rot. However, the water quality of the tank can also be the cause. Similarly, the bacteria that can cause fin rot lays dormant in all tanks. Nevertheless, it becomes dangerous to your Bettas when

  • the tank is dirty,
  • over-occupied, or
  • the fish becomes stressed or injured.


In general, these are the symptoms:

  • torn fins,
  • also, inflamed rays,
  • blackening or redness along the edge of fin or tail,
  • also, blood on the tips of fins, and
  • lastly, receding fin edges.


In general, if the fin or tail rot is in the earlier stages then you can clean the tank and aquarium maybe with salt. Meanwhile, once you are through, treat the infected area with 50% Mercurochrome with a cotton swab.

However, if the illness progresses, then antibiotics will surely be needed.

Also, you may add Almond leaf to the water after changing it as this releases a natural Betta antibiotic.

Fish Lice


Particularly, a crustacean parasite that feeds and lays eggs on the Betta fish causes this illness.


Accordingly, these are common symptoms:

  • ulcers,
  • wounds and
  • lastly, a round parasite attaches to the skin.


Specifically, using a pair of tweezers, gently remove the parasite from the Betta fish. However, if you leave large wounds behind, use cotton swab dab 50% Mercurochrome on the affected area.

Fungus / Fungal Infections

In particular, fungal infections are quite common among the Betta population.


Specifically, growths occur in previously damaged areas where there is damage to mucous/slime coating. However, fungal infections are contagious.


Generally, these are the symptoms:

  • cotton looking growths on the body,
  • pale in color,
  • also, disinterest in food, and
  • finally, lethargic.


In particular, spot treatment using 50% Mercurochrome with a cotton swab onto the affected areas. Also, use the same dose of medication daily and change water frequently until all fungus disappear.

Gill Parasites


Particularly, flukes cause this parasite.


Ordinarily, these are the symptoms:

  • struggle to breathe properly,
  • also, rubbing along the side of the tank,
  • next, glazed over eyes, and
  • finally, loss of movement.


Specifically, a veterinarian can best deal with this type of parasite.

Ich / White Spot

Generally, this is one of the most common illnesses among Betta fish. Also, Ich is present in the majority of fish tanks and aquariums. However, healthy Betta fish have a natural immunity to it.


Particularly, certain parasites called ichthyopthirius which uses the Betta as its host. Meanwhile, once it falls off, it multiplies in the bottom of the tank.

Thus, these new parasites then live off other Betta fish. Likewise, Ich can be carried out by frozen live food.


Generally, some of these symptoms include:

  • small white dots on the body and fins and in some cases the eyes,
  • clamped fins,
  • rubbing on ornaments and side of the tank, and
  • lastly, it may become less active.


In particular, use formalin or malachite green to treat the entirety of the tank. Also, if raising the temperature of your tank is an option, clean the tank and raise the temperature to 85 F/ up to 30 degrees Celsius.

Generally, these parasites cannot handle the heat so within a few days your fish will make a full recovery.

Intestinal Parasites / Internal Parasites

Also, these parasites live off any food that the Betta fish eats making them very lethargic and in a sense they become starved. Therefore, an owner must identify this early to treat the Betta fish in order for it to be successful.


Usually, parasites that often enter the tank through food such as brown worms cause this illness. Particularly, intestinal parasites are much rarer than external parasites in Betta fish.


Generally, these are

  • change in behavior,
  • lethargic and
  • weight loss while eating normally.
  • Meanwhile, intestinal parasites are contagious from one Betta to another.


Specifically, change out tank water and clean any objects that are going back into the tank. Also, add one teaspoon of aquarium salt to the new water.

However, if your fish does not improve after this, you will need to purchase antibiotics from specialized aquarium shops.


In particular, Popeye is a bacterial infection which causes the Betta’s eye to swell and protrude from the socket.


Generally, poor water quality from not enough water changes commonly causes popeye.


Specifically, one or two of the Betta’s eyes will swell up or protrude from the socket.


Usually, changing the water for a few days in a row can deal with popeye. Also, adding one teaspoon of aquarium salt per ten liters of water can treat it.

However, if the swelling does not reduce, you may need to purchase antibiotics.



In general, poisoning of your Betta is the direct result of an unsatisfactory tank leading to high levels of ammonia, nitrite, and nitrate.


Particularly, poisoned Betta fish have a tendency to stay at the top of the tank and gasp for air.


Accordingly, test the levels of ammonia, nitrite, and nitrate in the fish tank using an aquarium water test kit. Afterward, dispose of the water and fill the tank with clean water that has chlorine remover.

However, some suggest using bottled water for the tank because the levels of these things have already been previously tested.

Slime Disease

In particular, slime disease is common and caused by three different parasites. Likewise, slime disease weakens the Bettas’ immune system which makes them more prone to getting a secondary illness or disease.


Specifically, causes are

  • Costia,
  • Cyclochaeta and
  • Chilodonella parasites.


Accordingly, these are

  • Frayed fins,
  • grey/white coating on the body of fish that looks like mucus,
  • loss of appetite,
  • inactive and
  • lastly, cloudy eyes in some cases.


Ordinarily, perform frequent daily water changes for up to a week and use malachite green. Likewise, the use of aqua salt for up to ten days is best to cure slime disease.

Swim Bladder Disease

In general, not as common as other diseases in Betta fish, swim bladder disease is more common in younger Bettas. However, this illness is not infectious.


Specifically, caused by a bacterial infection that is usually the result of the previous injury from transportation or fighting among Betta fish. Similarly, swim bladder disease can be the result of overfeeding or poor water quality.

Also, swim bladder in female Betta fish can be the result of damage during mating.


Accordingly, these are

  • difficulty and abnormalities when swimming,
  • swimming on the side,
  • difficulty swimming upward,
  • loss of balance when swimming and
  • Bettas abdomen swelling up.


Generally, a Betta will cure itself within a few days. Although to cure a Betta fish with swim bladder disease, one must administer an antibiotic. Likewise, making the water shallower helps the Betta fish to breath and feed easier.

Tips to Ensure Your Betta Remains Happy and Healthy

Particularly, once you diagnosed your Betta fish with a particular illness and medicated as needed. In general, there are a few things you can do regularly to ensure your fish stays happy and healthy.

Therefore, it is important to remember when housing a Betta fish that prevention is always better than cure. Thus, it is best for you:

  • Clean your tank or betta fish bowl regularly
  • Check pH levels of the water
  • Quarantine new betta fish that you bring home
  • Add aquarium salt
  • Ensure you don’t overfeed your betta fish
  • Remove dead fish from a tank immediately for the safety of other betta fish in the tank
  • Ensure the water is very warm

Create Your Bettas’ First Aid Kit

Particularly, like most pet owners, you are likely to already be attached to your Betta fish. Ordinarily, this means that you are ready to care for it like you would for any other pet.

Also, this means that you should always have a first aid kit handy for your fish. Ordinarily, it may sound absurd to create a first aid kit for a Betta fish.

However, the truth of the matter is that the medications most often required to treat Betta fish diseases are not available in most pet stores.

Therefore, if the time comes that your Betta fish is ill, having these kits will go a long way in helping them. Also, you may want to have these kits available in case your mail order for medication for your fish’s treatment takes too long to arrive.

Therefore, in any case, as a responsible Betta fish owner, you should always have a basic first aid kit available to treat the most common Betta fish diseases.