25 Betta Fish Diseases, Symptoms and Treatment Guide ( With Pictures)

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Betta Fish Diseases

Bettas are extremely hardy fish and will survive conditions that would kill other species in a short time. Betta Fish can get sick easily but most betta fish diseases are curable. At the time of daily feeding, we should make it a habit to observe the bettas. Overtime, our eyes will get trained to recognize a sick betta fish. As a betta fish lover, it is necessary to be aware of the betta diseases and be prepared to medicate a sick betta.

Early signs of sickness

A healthy betta fish eats like a pig and is very active swimming around the tank. It remains colorful and very vibrant. A sick betta fish does not eat or eats reluctantly and may spit out his food. When it looks pale or its colors get dull or turn grey, it is a sure sign of a betta fish sick. The body may have open sores, white cottony patches, red and white spots. One or both the eyes may be swollen or protruding.


Betta fish suffer from a variety of health issues, but the good news for keepers is that these issues can be avoided and treated. If the infections occur in the aquarium, they are easily identified and effectively treated.

This article discusses all of the most common betta fish diseases and illnesses, as well as their prevention, diagnosis, treatment, and cure. If you have a Siamese fighting fish at home, keep reading to find out how to keep your aquatic pet healthy.

Also Read : 8 Easy Steps on How to Breed betta fish

Betta fish illnesses and diseases are classified as fungal, parasitic, or bacterial. The majority of fungal infections are the result of pre-existing medical conditions. Parasitic illnesses are the most contagious, and new fish can introduce them into the aquarium. The most common causes of bacterial illnesses are poor water quality and improper fish handling techniques.

25 Common Diseases on Betta Fish

  • Fin and Tail Rot
  • Columnaris
  • Hemorrhagic
  • Dropsy
  • Pop Eye
  • Eyecloud
  • Mouth Fungus
  • Furunculosis
  • Fish Fungus
  • Velvet, or ‘Gold Dust Disease’
  • Ich, Ick, or ‘White Spot Disease’
  • Anchor Worms
  • Hole in the Head
  • Swim Bladder Disease / Swim Bladder Disorder (SBD or Bloat)
  • Betta Tumors
  • Ammonia Poisoning
  • Bacterial Infection/Open Red Sores
  • Constipation
  • Costia
  • External Parasites
  • Internal Parasites (intestinal)
  • Inflamed Gills
  • Septicemia
  • Slime Disease
  • Tuberculosis
1Fin and Tail RotThis disease, as the name implies, affects the fins and tails of betta fish. Bacteria or fungi can cause it.As a result of rotting, the fins and tail appear to melt away or discolor.
2ColumnarisThis is a bacterial infection that causes rag and fraying of the fins.Skin ulcers or lesions, white spots or marks on the mouth, cottony growth on the mouth, scales and fins discoloration, and gill discoloration are all symptoms. As a result of the gill infection and damage, the fish may have difficulty breathing.
3HemorrhagicHemorrhagic, also known as redmouth, causes severe bleeding inside the fish’s mouth and eyes.bleeding inside the mouth and eyes of the fish.
4DropsyThis is a potentially fatal kidney disease. As a result of internal fluid accumulation, infected fish may develop a swollen belly or abdomen.outward-sticking white scales and sunken eyes.
5Pop EyeThis condition results in swelling of one or both eyes. The swelling could be caused by a tumor or a viral infection.Pop Eye on Betta Fish
6EyecloudThis disease, also known as cloudy cornea, causes white films on the eyes.You may notice a buildup of mucus as your Betta fish’s body begins to fight off an infection, as well as what appears to be a fungus on his eye.
7Mouth FungusThis is a bacterial disease that causes white lines or clumps around the fish’s lips and mouth.Symptoms can also appear on certain parts of the betta fish’s body, such as the abdomen and gills. Symptoms also include abnormal swimming patterns and an inability to swallow food.
8FurunculosisFurunculosis is a highly contagious disease that affects all species of fish.Furunculosis is characterized by red and open sores on the fins and tail of the betta fish. Fish Fungus causes white bumps or lumps on the betta fish’s skin.
9Fish FungusThis is a fungal infection caused by previous infections.Patches on the skin of fish that appear smooth or slimy. These patches could be white, gray, or milky in color, and they would be flush with the skin. On the outside, blood and raw flesh may appear. Parts of the bettas’ skin will dissolve away as the illness progresses.
10Velvet, or ‘Gold Dust Disease’Oödinium pillularis or Oödinium limneticum causes velvet. Amyloödinium ocellatum causes the dreaded Coral Fish Disease in marine fish.loss of color, fins clamped against the body, and labored breathing.
11Ich, Ick, or ‘White Spot Disease’Ick, also known as white spot, is a parasitic disease.white dots, rings, marks, or spots on the belly, fins, tail, gills, and other parts of the skin of betta.
12Anchor WormsThis is a parasitic infection that affects the tail or fins.The affected areas are red and swollen, with protruding worms and slime threads.
13Hole in the HeadHole in the HeadBettas with a hole in the head have an abrasion on the head that looks like a pinhole or white fuzz.
14Swim Bladder Disease / Swim Bladder Disorder (SBD or Bloat)This disorder, also known as flipover, causes the fish to float at the surface of the water.swims sideways or upside-down and can also be found at the tank’s bottom.
15Betta TumorsBetta tumors are typically cancerous lumps, growths, or minor bumps/cysts under the fish’s skin.They are caused by genetic mutations and viral infections and primarily affect the reproductive organs, gills, tail, and abdomen.
16Ammonia PoisoningAmmonia (NH3) is a weak base that causes gill burns.The main symptom is gasping for air at the surface, which is accompanied by darting motions.
17Bacterial Infection/Open Red SoresBacterial infections come in a variety of forms. It’s highly contagious. The risk of death varies, but it should always be taken seriously and treated as soon as possible.Red sores or red patches, loss of appetite, loss of color, clamped fins, sitting at the bottom or top of the tank, and not moving
18ConstipationDifficulties excreting waste as a result of a digestive blockage. Non-contagious, but potentially fatal if left untreated, and a very common problem!Bloating of the abdomen, inability to defecate.
19CostiaInfected fish introduced a contagious parasitic infection to the tank.Cloudy, milky skin with protruding flagella (parasite appendages). Fish may scratch and exhibit a loss of appetite.
20External Parasitesparasitic creatures that live on the betta’s exterior (such as anchor worms). It is potentially fatal, but it is easily treatable.Scratching and darting motions Under magnification, parasites are usually visible.
21Internal Parasites (intestinal)Nematodes, for example, are protozoa that live inside fish (roundworms). Direct observation is not possible. If left untreated, it is usually fatal. Although not contagious, an entire aquarium system can become infested.Betta is losing weight despite having a healthy appetite because the parasite is stealing nutrients.
22Inflamed GillsA swelling of the gills that prevents them from closing completely or partially. It is fatal because it prevents the fish from breathing properly.One or both gills will become swollen and red, and they will fail to close properly. Betta will almost certainly be gasping for air.
23SepticemiaIt is a blood infection, also known as Sepsis. In a short period of time, it can be fatal. Although the condition itself is not contagious, the bacteria that causes it may be.Under the scales, there are red spots or streaks. Symptoms include ulcers or open wounds, loss of color, loss of appetite, lethargy, and clamped fins.
24Slime DiseaseAn infection with one of the parasites Chilodonella uncinata, Icthyobodo, or Trichodinia. Contagious, with a high mortality rate.Betta will produce a lot of slime (mucus) that will appear to be sloughing off the fish in the beginning. Scratching, loss of appetite, and heavy breathing are all symptoms of the later stages.
25TuberculosisA highly contagious bacterial infection that is almost always fatal to fish. It has the potential to spread to humans.Lesions, loss of scales, extreme weight loss, and skeleton deformation

Fin and Tail Rot

Fin and Tail Rot in Betta Fish

How to cure and treat of Fin and Tail Rot

Although fin rot is common, it is easily treated. To kill the bacteria that causes fin rot, medications such as Melafix and Aquarisol are usually added to the aquarium water. The most effective way to treat Fin Rot is to use a product like Melafix to kill the harmful bacteria in your aquarium.


Columnaris in Betta Fish

How to cure and treat of Columnaris

Furan-2 is a popular treatment method for betta fish with columnaris; however, you should also use aquarium salt in addition to Furan 2. Kanamycin is another well-known antibiotic that can be used to treat them. There are also medicated fish food options that can be beneficial. Look for any Oxytetracycline-containing products.


How to cure and treat of Hemorrhagic

Bettas dislike flakes and will only eat them as a last resort. If the betta spits out its food, don’t be alarmed. Antibiotics such as ampicillin can be used to treat hemorrhagic disease. The condition, also known as redmouth hemorrhagic, causes severe bleeding inside the fish’s mouth and eyes.


Dropsy In Betta Fish

How to cure and treat of Dropsy

Dropsy is a dangerous condition that can quickly kill a fish. In order to treat betta fish dropsy, you must do the following:

  1. Transfer the betta fish to a different tank. If the infected betta exhibits symptoms, it should be removed from the aquarium immediately. In the second tank, add one teaspoon of salt to one gallon of clean water. This will assist in keeping the sick fish in a sanitary and clean environment.
  2. For nutrition, provide nutritious foods. If the symptoms of dropsy are detected early on, the fish should be fed nutritious foods to boost its immune system. However, as the infection progresses, the infected fish typically loses interest in eating and it becomes more difficult to nourish it with quality food in order to strengthen it.
  3. Make use of antibiotics. It has been demonstrated that killing the bacteria that causes dropsy can be accomplished by adding antibiotic medication to the betta’s water. If the antibiotics are added to the water as directed by the vet or manufacturer, this type of treatment can usually be cured within a week of detection. In most cases, this type of betta fish dropsy treatment must last at least 10 days in order to completely eradicate the bacteria that causes dropsy.

Pop Eye

Pop Eye in Betta Fish

How to cure and treat of Pop Eye

There are several antibiotics that, when added to the betta fish’s water, will cause the popeye to go away. These antibiotics are typically available at pet stores. Fill the fish tank with ampicillin and change the water every third day. Apply the medication for a week after your fish’s popeye has gone away.

Eye Cloud

Eye Cloud in Betta Fish

How to cure and treat of Eye Cloud

One of the more treatable diseases is cloudy vision. If you notice it and act quickly, your betta will be fine in no time. Here are the steps you must take.

  1. If your betta is in a community tank, move him to a quarantine tank as soon as possible. (If you don’t already know how to set up a quarantine tank, now is the time to learn.)
  2. Set up your quarantine tank as usual and fill it with conditioned water. (Don’t forget to wait 24 hours before adding your betta.)
  3. Slowly introduce your betta to the quarantine tank after 24 hours. Make sure to float him for 20 minutes on the surface in a bag before adding him to the tank.
  4. After you’ve added your betta to the tank, you should add some aquarium salt. 1 tablespoon per 5 gallons is sufficient. Before adding the aquarium salt, mix it in a small amount of aquarium water until it’s diluted.
  5. In addition to aquarium salt, API stress coat can be used. This will help to relieve your betta’s stress and build up his slime coat.
  6. When changing the tank’s water, only add more aquarium salt and API stress coat.
  7. While you’re at it, you should also change the water in your main tank. If your tank is 5 gallons, you should change the water every 3-4 days. If it’s less than 10 gallons, you can do a 25% water change every 3 or 4 days. And as the tank grows in size, you can change less water in less time.
  8. You should test your main tank because poor water quality is the leading cause of cloudy eyes. Your tank should have no more than 20ppm nitrate, no more than 0ppm ammonia, and no more than 0ppm nitrite. If you notice more than this, you should keep changing the water until it reaches that level.

Mouth Fungus

Mouth Fungus in Betta Fish

How to cure and treat of Mouth Fungus

For Mouth Fungus, clumps or white lines will appear on the betta fish’s mouth, preventing them from eating and swallowing food properly. In terms of treatment, a water conditioner should suffice, but medications are also available if the bacterial infection becomes severe.


Furunculosis in Betta Fish

How to cure and treat of Furunculosis

A parasitic disease that causes white dots or spots on the skin of betta fish is known as White Spot, Ich, or Ick. It can be avoided by changing the water on a regular basis. Fish-zole, Malachite Green, and salt baths can be used to treat the illness. It is very simple to deal with the illness if treatment begins as soon as possible.

Fish Fungus

Fish Fungus in Betta Fish

How to cure and treat of Fish Fungus

This fungal treatment should be added to the water in your fish tank, and all filters and invertebrates should be removed before administering any treatments. Other medications that work well for the treatment of fungal infections in betta fish in home aquariums include Erythromycin, Triple Sulfa, Maracyn Two, and Fungus Care.

Velvet, or ‘Gold Dust Disease’

How to cure and treat of Velvet

There are three things you’ll need to do right away to treat velvet in your betta. Heat, salt, and obscurity. The parasite that causes velvet will die if it is deprived of light and placed in an environment that is saltier and hotter than it is accustomed to. Fortunately, the disease can only survive for a few days without a host before dying. So, to treat velvet, take the following steps:

  1. The first step is to heat up the water. The parasite that causes velvet will die at higher temperatures, so raise the temperature to 82-85°F while treating your betta. Make sure you don’t raise the temperature too quickly or your betta will die from shock. Rather, gradually raise the temperature by 1°F every 24 hours.
  2. Simultaneously, while treating your betta, you should dim the lights in your tank. The parasite that causes velvet has chlorophyll in its cells as well, allowing it to use photosynthesis.
  3. The final step is to fill your tank with aquarium salt. Slowly reintroduce the salt. Remove some water from your tank and dissolve the salt in it before reintroducing it. For every gallon of water in your fish tank, add 1 teaspoon of salt. To avoid shocking your fish, add the salt gradually over 3-4 hours.

Ich, Ick, or ‘White Spot Disease’

Ich in Betta Fish

How to cure and treat of Ich

Antiparasitic medications designed for use in fish are the most effective treatment for ich. Some medications can be lethal to snails and other invertebrates, so use caution if you have invertebrates in your Betta’s tank.

Anchor Worms

Anchor Worms in Betta Fish

How to cure and treat of Anchor Worms

To cure anchor worms, a combination of manual removal, treatment with potassium permanagate, salting the aquarium, and, if possible, removing your betta to a quarantine tank for a month is required. The best way to keep anchor worms at bay is to quarantine any new additions to your tank.

Hole in the Head

Hole in the Head in Betta Fish

How to cure and treat of Hole In the Head

Metronidazole is the most commonly prescribed medication for hole in the head disease. In most cases, it can only be obtained by visiting a veterinarian, who may prescribe medicated fish food or a mixture you can add to the water if your fish has stopped eating.

Swim Bladder or Bloat

Swim Bladder in Betta Fish

How to cure and treat of Swim Bladder

If the swim bladder disease is caused by a bacterial infection, the infection should be treated with a broad-spectrum fish medication. You can also supplement your tank with aquarium salt. A minor injury to your betta fish will heal on its own, but a serious injury can be fatal. Never feed your betta fish too much.

Betta Tumors

Betta Tumors in Betta Fish

How to cure and treat of Betta Tumors

Betta Tumour Treatment Tumors in fish are difficult to treat, and there are no cures for either benign or cancerous tumors. While the fish is under anesthesia, a professional can remove benign tumors. Tumors cannot be treated with medications, and prevention is more effective than cure.

Ammonia Poisoning

Ammonia Poisoning in Betta Fish

How to cure and treat of Ammnia Poisoning

The only way to successfully treat ammonia poisoning in your Betta is to ensure that the ammonia levels are reduced to 0 ppm. Adding an ammonia detoxifier to your tank is the quickest way to restore normalcy to your tank. You should use the ammonia detoxifier whenever the ammonia levels rise above 0 ppm.

Bacterial Infection/Open Red Sores

Bacterial Infection/Open Red Sores in Betta Fish

How to cure and treat of Bacterial Infection/Open Red Sores

Tetracycline can be used to treat a variety of internal and external bacterial infections in bettas and other tropical freshwater fish. Remember that this medication should not be used to treat bettas with dropsy or kidney disease that has developed for another reason, and it should only be used in freshwater aquariums.


Constipation in Betta Fish

How to cure and treat of Constipation

Aside from peas, daphnia is a popular treatment for betta fish constipation. If you notice your betta has a bloated belly, difficulty swimming, or a loss of appetite, it’s critical to act quickly before the problem worsens. It is not difficult to treat the digestive problem with water fleas.


Costia in Betta Fish

How to cure and treat of Costia

Copper (add 2mg per litre water) or Acriflavine (trypaflavine) are the two sure ways to treat costia (add 1ml per litre water). Acriflavine (trypaflavine) can cause sterility in fish, so it is critical not to overdose on it. Copper, on the other hand, can poison your fish and even kill them if consumed in large quantities.

External Parasites

External Parasites in Betta Fish

How to cure and treat of External Parasites

You should consider getting some Betta Revive to treat external parasites. You can get this copper-based treatment for Betta fish at your local pet store. Before using it, you should follow the instructions and perform a high percentage water change.

Internal Parasites

Internal Parasites in Betta Fish

How to cure and treat of Internal Parasites

Internal parasites in your betta fish can be treated with medications such as mebendazole, pyrantel pamoate, and albendazole. How long does a fish take to poop? Fish poop may cling to the fish’s body for a minute or two before falling to the ground. If it does not fall for an extended period of time, it could be a sign of constipation.

Inflamed Gills

Inflamed Gills in Betta Fish

How to cure and treat of Inflamation Gills

Add a good water conditioner, preferably one that eliminates chlorine, chloramines, and heavy metals while also neutralizing ammonia, such as Kordon’s AmQuel+ and NovAqua combined. While adding aquarium salt to the water isn’t usually necessary for Bettas, it can help improve gill function in fish that have been exposed to nitrite.


Septicemia in Betta Fish

How to cure and treat of Septicemia

Antibiotics, which you can get from your veterinarian or over-the-counter at your local fish store, are the best way to treat suspected cases of septicemia in bettas. The idea behind water-soluble medication is that the antibiotics are absorbed by the fish.

Slime Disease

Slime Disease in Betta Fish

How to cure and treat of Slime Diseases

Yeast infections can occur whenever the betta slime layer is damaged. A afflicted fish appears to have cotton attached to its body. A fungicide is added to the tank as part of the treatment. You may also need to use methylene blue or gentian violet on your fish.


Tuberculosis in Betta Fish

How to cure and treat of Tuberculosis

Tuberculosis is a life-threatening disease in betta fish, and some do not survive treatment. Only about 10% of betta fish with severe tuberculosis infections survive treatment with the assistance of a professional. When treating this infection, you may need to consider using a strong antibiotic.


Prevention is always preferable to treatment. There are many ways to avoid Popeye infections, and here are a few of them:

  1. Maintain regular water renewals. A 20 percent water change should be performed on an average-sized betta tank (5-10 gallons).
  2. Incorporate a large number of live plants into the tank.
  3. Feed your betta a protein-rich diet that is low in plants.
  4. To prevent the growth of certain pathogens, use a natural aquarium tonic.
  5. Using a pre-set heater, keep the temperature between 77°F and 82°F.
  6. Medication should not be mixed as this will reduce their effectiveness.
  7. Keep no sharp or pointed objects in the tank.
  8. Your betta should only be kept with other small peaceful fish.
  9. Before introducing new fish or invertebrates (snails and shrimp), quarantine them for 6 weeks. As a result, the risk of disease transmission from fish to fish is reduced.
  10. Before using new tank supplies or items in the tank, thoroughly wash them.
  11. To avoid spreading pathogens from different tanks, use separate equipment for each tank; washing in between does not always work.

People Also Asked For

Why is my betta fish turning white?

Fin rot is a common disease that affects aquarium fish. Bacteria cause the disease, which causes the fish’s fins to turn white around the edges and develop a ragged, split appearance. You must treat this disease as soon as possible to prevent it from spreading to the betta’s body or causing permanent finnage damage. I’m sorry (White Spot Disease)

Why is my betta fish turning black?

Stress, old age, injury, and illness can all cause your betta to lose color. Bettas can also naturally lose color, especially if they have the marble gene. If your betta is turning black, you shouldn’t be too concerned unless they’re also exhibiting other symptoms of illness.

Why is my betta’s tail shredded?

Your betta fish may bite its own tail for a variety of reasons. This could be due to increased stress in your betta fish, boredom, or the betta fish’s aggressive nature. If you do not have another fish in the tank with your betta, this is another likely cause of shredded fins overnight.

Why is my betta fish fins stuck together?

If your betta fish has died as a result of a disease, which is the root cause of those clamped fins, it’s most likely due to poor water quality. Alternatively, poor water quality could be the culprit. And improving that may bring your fish back to life. First, can we all agree that maintaining proper water conditions in a small bowl is difficult?

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