23 Betta Fish Diseases, Symptoms and Treatment Guide

Have you been noticing some weird changes in your betta fish lately? Like it not being able to swim in its usual way or have a change in its appearance. Well, this might be because your fish may be going through some health trauma.

Betta fish can suffer from several diseases coming from bacterial, parasitic, or fungal issues. But the good news for all betta fish keepers is that these conditions are treatable and can be prevented, especially if the infection has occurred in the aquarium. It can be easily identified and then treated accordingly.

If you’re an owner of these beautiful fish then fortunately for you, you’ve come to the right place, as here I am going to share all the relevant details on the infections, their symptoms, and treatment for your fish. For basics, you must know that to prevent the disease from spreading or emerging; it is very important to keep the water clean and to handle the fish carefully.

Before moving ahead, let’s talk about the beauty of betta fish also known as the Siamese fighting fish. They have a short life span of two to three years. It is said and well defined that these fish are not only easy to take care of but they come in the most beautiful vibrant colors out there. Just like any other aquarium fish, however, betta fish requires a certain amount of extra care as they are prone to many diseases.

Table of Contents

Types of Betta Fish Diseases

There are many diseases that the betta fish might surrender to, thus they can be categorized into three types being, fungal, bacterial, and parasitic. You need to know the nature of the disease as it makes it easy to treat them because you know what to do when you see a problem in your fish.

Fungal Disease

Fungal infections occur when there is another problem in your fish that already exists, such as an injury. This gives life to the fungus to emerge on the fish and harm it. This growth can be extremely harmful to your fish as it can make it fatal. Thus, treating it is very important. Fungal diseases are treated with the help of antibiotics and antifungal medicines as prescribed by the vet.

Bacterial Disease

Just like fungal diseases, bacterial diseases are also caused until an opportunity for it arises, such as weakness in the immune system due to stress, injury, or wound. As you should know that bacteria live with the fish at all times so it is not a problem for it to harm your fish therefore you have to be extra careful and take appropriate prevention measures. These bacterial diseases can be treated with the help of antibiotics.

Parasitic Diseases

Parasites are the last thing that you would want in your fish’s tank, trust me when I say this, I mean it because they can cause so much harm to your fish and damage their health. Parasites attack the tank when the fish is contaminated or the water is not clean. Thus, it is your responsibility to take care of it by cleaning the water and adding salt to it is the best treatment and prevention.

Common Betta Fish Diseases and their Symptoms, Treatment & Prevention

As I stated above, there are many diseases that your betta fish might get into contact with within its life, so here is a complete list of all the diseases and a guide on the detail of these diseases, their symptoms, and their prevention and treatment.

Ammonia Poisoning
Bacterial Infection/Open Red Sores
Constipation
Costia
Dropsy
External Parasites/ gill parasites
Betta Fish Fin Rot or Tail Rot
Fungal Infection (mouth fungus)
Ich, Ick, or ‘White Spot Disease’
Inflamed Gills
Internal Parasites (intestinal)
Popeye
Septicemia
Slime Disease
Swim Bladder Disease / Swim Bladder Disorder (SBD or Bloat)
Tuberculosis
Velvet, or ‘Gold Dust Disease’
hole in the head
columnar
Hemorrhagic
Furunculosis
Anchor worms
Betta tumors

1. Ammonia Poisoning

This disease is most commonly found in unfiltered tanks that causes burns to the gills of the betta fish. Ammonia is found in fish waste which means it is caused if the water is not clean then the fish can catch it.

The symptoms of ammonia poisoning are when the fish is gasping for air at the surface and darting motions.

This disease can be treated by changing the aquarium water more consistently to get rid of the already existing waste. And secondly, limit or reduce the amount of food fed to the fish for some days to lessen the ammonia output.

2. Bacterial Infection / Open Red Sores

Bacterial infections are highly contagious and they should be taken seriously and treated right away as soon as possible to avoid any problems later on. It is a very common form of the disease among betta fish as bacteria already exist in the water with the fish, the disease is only caused when the bacteria are given a hand to spread themselves. It spreads when the immune system of the fish is not strong due to stress, there is an injury or wound on the body of the fish which gives life to the bacteria and leads to infection to form eventually.

The symptoms of bacterial infection are red sores or red patches, loss of appetite, clamped fins, sitting on the surface or bottom of the tank, not moving, and color loss.

You can treat this infectious disease by cleaning the water and isolating the infected fish separate from the uninfected by adding aquarium salt to it separately. Moreover, you can treat it by using Sulfa, Tetracycline, or Erythromycin.

3. Constipation

This is a noncontagious disease that is very common among betta fish. It is also very curable and needs to be treated right after the issue is detected if not done then the disease can become fatal.

This can be caused by overfeeding your fish, feeding it dry food instead of frozen food that is easily digestible, or the food that you feed lacking fiber Symptoms include the bloating of the belly, not showing interest in food, and difficulty passing feces.

To treat your betta fish for constipation, try the three-day fasting method, do not give food to your fish for three days so that it can digest the already existing food naturally. But if this does not work then you can feed then the inside of the peas after boiling them as they also help in getting rid of constipation. You can even give a small number of daphnia to help with constipation. And once your fish is finally able to pass its waste then it is important that you cut the amount of food you were feeding it previously to avoid it to happen again. And if needed you should also contact the vet to recommend a new diet for your fish.

4. Costia

This is a very rare disease occurred among betta fish. This disease can come about when an infected fish with a contagious parasitic infection is added to the tank. This infection is caused by protozoa Ichthyobodo necatrix, also termed Costia necatrix.

If you think that your fish is acting weird lately then you should look for these symptoms, maybe it is affected by Costia. Loss of appetite, cloudy, milky skin, protruding flagella from the parasites, and scratching itself.

For treatment of this disease, it is best to isolate the infected fish in a quarantine tank. And salt the aquarium or use Trypaflavine. Also, increase the temperature of the aquarium to 90 degrees for three days to kill the leftover parasites.

5. Dropsy

Dropsy is a deadly disease that affects the kidneys of the fish. It is rare, but it is very important to know the symptoms and signs so that if you feel like your fish suffering from it you can treat it in time and also isolate it from other fishes. It is also said that if the fish has dropsy and is still alive then the disease is not contagious but is fatal.

Dropsy can be caused by many reasons such as the bacteria entering the tissue of the fish which damages its internal organs, the bloating of this disease is caused by fluid retention in the fish, poor quality water, bad tank conditions, the fish might in stress when transporting, lack of nutrition and the temperature of the water may also have dropped which led to this disease to build up inside of the fish.

If you feel like your fish is suffering from dropsy then here are some symptoms that you should keep in mind before diagnosis your fish, bloated body, lack of food consumption, scales may have raised, the appearance of your fish may be in a pinecone, and lastly, the fish becomes inactive.

Sadly, if your betta is diagnosed with dropsy then there is no proper cure/ treatment, or in simple words, your fish may not survive. But you could use Metronidazole, Tetracycline, or edible Anti-fungal pellets to relieve some of its pain.

6. External Parasites / Gill Parasites

These external parasites such as anchor worms live on the outside of the fish. These are fatal but can be cured. This is a common disease that is occurred among the betta community. But can be avoided by quarantining the affected specimen.

The cause of this disease is flukes or the introduction of new fishes to the tank. This can also be caused by other aquarium creatures.

The symptoms that you are probably going to see when your betta is infected with parasites are darting motion, difficulty in moving, scratching, the fish is probably going rub its body along the tank, it will face struggling to breathe, and glazed eyes.

The best way to treat these external parasites is by changing the tank water frequently, you can use aquarium salt, or if the salt is not working out then you can use an anti-parasitic medication, such as Tetra Parasite Guard or any other medicine such as recommended by your vet to help get rid of these annoying parasites.

7. Betta Fish Fin Rot/ Tail Rot

Fin and tail rot is a very common disease that is found in betta fish. This disease can be caused by any of the two, bacteria or fungi. This disease starts at the end of the tail of the fish and then makes its way to the body in different stages. This is a nonfatal disease unless it gets too extreme conditions. The rotting of the fins and tail causes it to fall off the fish but it can grow back after it is cured, but it would not be the same vibrant way it was before.

This disease can be caused when there is a fight between two betta fish that leads to peeling of the tail, or the main cause is the quality of the water in the tank. If the water is dirty, then this gives an extra hand to the already existing bacteria that attack the fish. There is also another reason for the cause of this disease, you might have handled your fish roughly and may tear the tail.

The symptoms of tail and fin rot are very obvious, the torn or frayed tail and the affected edges are sometimes lined with black or white. This is how you may understand that your fish is going through this disease.

You can treat this disease by first, cleaning the tank and water to get rid of the bacteria, and adding aquarium salt to it. You can also use anti-bacterial medication to prevent this disease from spreading.

8. Fungal Infection

This is a very common infection that is found in the betta community. The fungus grows on the exterior of the fish. This infection is fatal if it is not treated in the early stages. And this infection is highly contagious. This infection is formed usually after another infection or injury, or on the areas where the mucus/ slime coating has been damaged. This is more of an opportunistic infection.

The main symptoms of this infection are the white cotton-like patches found on the fish’s body, Lethargy, muted color, loss of appetite and clamped fins are other symptoms of fungal infection.

This infection can be treated by isolating the fish separately if it is part of a whole community, consistent water changes and antifungal medication is the way to rid of this infection.

9. Ich, Ick, or ‘White Spot Disease’

This disease is scientifically known as Ichthyophthirius multifiliis. This is a highly contagious disease very commonly found in betta fish. It is a parasitic infection but it responds well to treatment and can be cured if found early.

The symptoms of itching or white spot disease are, small white flakes like salt on the body of the fish, hiding, loss of appetite, stress, scratching itself, and resting on the bottom.

You can help your fish to get rid of this infection by raising the water temperature to 80 to 85 degrees F, and you can use anti-parasitic medication or an ick-specific medication. You can also use formalin or malachite green to cure your fish of this disease.

10. Inflamed Gills

This is yet another one of the many common diseases found in betta fish. This is a fatal disease that leads to swelling of the gills and makes it difficult for the fish to breathe. When a betta is infected with this disease their gills don’t close or partially close, that is why the fish faces difficulty in breathing.

The reasoning or cause of inflamed gills includes bacterial infection and ammonia/nitrite/nitrate poisoning.

When it comes to symptoms, it again has some very obvious symptoms such as the betta gasping for air, and the gills of the fish will be both swollen or red and won’t close properly.

You can treat this infection by isolating the infected fish and doing a water change every three days. You can then check your water or get it checked to see if the water quality is the culprit. Water changes should be enough to treat the disease if not then you can use antibiotics for infection or poisoning.

11. Internal Parasites (intestinal)

Getting Intestinal parasites is again common for betta fish. These parasites live on the food of the betta making them lethargic and making them starved. They live inside the fish such as roundworms and therefore cannot be observed directly. This disease is not contagious but can be fatal if not treated in time. as you know by now that the parasites are usually bought in by the new fish carrying parasite eggs along with them. This is the reason for the cause of this disease.

And the symptoms of this disease are that the betta will be losing weight even though it consumes the same amount of food, this is because the parasites will be stealing it from inside.

To treat this disease, you will have to do a 100 percent water change daily to remove eggs and parasites, and you can also use anti-parasite fizz tabs or pellets.

12. Popeye

Exophthalmia is yet another disease commonly found in betta. It is a bacterial infection that causes one eye or both the eyes to swell, this swelling can be anything such as a tumor or a viral infection. This disease is contagious depending on its cause. It is very important to treat this infection as soon as it is detected as otherwise, betta can lose its eye or both the eyes.

This is usually caused by poor water quality, infection, rough handling or injury, gas embolism, tumors, or Vitamin A deficiency.

The symptoms of this infection are that one or both the eyes will be swelled up and in extreme cases, there are chances that the eye might pop out of the socket.

This infection can be difficult to treat because its cause is not evident thus you should keep the water clean, and use antibiotics, and/or Bettafix to cure the disease.

13. Septicemia

Septicemia known as sepsis is a common infection among betta fish. This infection is in the blood. The condition itself is not contagious but the bacteria spreading can be. This disease can also become fatal in a short period.

This infection occurs in a fish if it has an open wound or through ingestion.

The symptoms of this infection are many such as red spots or streaks under the scales of the betta, open wounds, loss of color, loss of appetite, lethargy, and clamped fins.

This infection should be treated urgently with antibiotics for both the gram-positive and gram-negative bacteria. Use medications with Metronidazole in it.

14. Slime Disease

Slime disease is a rare disease among the betta community, which is caused by three types of different parasites, Chilodonella uncinata, Icthyobodo, and Trichodinia. This disease is contagious with a high mortality rate. This disease weakens the immune system of betta which makes them more prone to secondary illness and diseases.

The symptoms of slime disease are that betta will be producing a lot of mucus/ slime in the early stages of the infection. In later stages, the fish will lose its appetite, breath heavily, and will bring scratching. There are some rare situations where your fish might have inactive and cloudy eyes in some circumstances.

To treat this disease, keep the water clean, do frequent water changes, and use aquarium salt for up to 10 days, as it has been proven to be the most effective way to cure slime disease.

15. Swim Bladder Disease / Swim Bladder Disorder (SBD or Bloat)

Swim bladder disease affects the swim bladder, an internal organ of the fish. It is not commonly found in betta fish but is surely found in younger fish. It is more of a symptom of another disease than a disease itself. This disease is noncontagious and rarely fatal.

This disease can be caused by damage to the swim bladder in case of any injury that the fish might have gotten in contact with. This can also result in pressure due to constipation, or overfeeding the fish.

The symptoms found for this disease are that the fish might face trouble keeping its balance while swimming, it might face difficulty during swimming, bloating, and the betta may rest on the surface of the water or at the end ground.

To treat this disease first it is important to know the cause, that is if the swim bladder is affected due to constipation, then you should try using the 3-day fasting plan to get rid of constipation or feed the inside of the peas. Or if the disease caused due to any injury, then let it heal, and afterward, the disease is going to heal on its own.

16. Tuberculosis

This is a rare disease that betta catch. Tuberculosis is a bacterial infection that is highly contagious and lethal to fish. It can make your fish ill for no apparent reason. This disease has fast progress and you might even know that there is something wrong with your fish until it takes its life away. This disease can also be transferred to humans. Be very careful in inspecting your fish for TB as many humans have caught this deadly disease from their fish.

The symptoms of TB include open wounds, Lesions, fin and tail rot, extreme weight loss, deformation of the skeleton, and loss of scales.

To be exact there is no such cure found for TB in betta fish, which means that your fish will die once it has come into contact with this disease. You may want to be cautious by changing the water daily and throwing out all the stuff that might have come into contact with your fish to avoid any other diseases to build up.

17. Velvet, or ‘Gold Dust Disease’

It is a common parasitic infection that your betta might come into contact with in its life. This disease is contagious and can harm or attack other fishes as well. A parasite known as Piscinoodinium attacks the betta by attaching itself to the betta skin.

Anything such as cool water temperature, high light, poor water conditions, and stress attracts parasites to the fish and causes velvet.

The symptoms of this disease are a layer of copper or gold dust on your fish, loss of appetite, heavy breathing, clamped fins, and scratching itself against the tank walls.

You can treat this infection by reducing the light beam so that it reduces the strength of parasites to photosynthesis. And also raise the temperature of the tank to 85 degrees F. clean the tank frequently, and use anti-parasitic medication or something with copper sulfate to kill the parasites.

18. Hole in the Head

This is a parasitic infection, when a betta is infected with it, they can die if they are not treated earlier.

The symptoms of this disease are tiny pinholes or white fuzz on the head.

The cure or treatment of this disease is by using an antibiotic. There is one known as parasite clear that works the best.

19. Columnaris

This is a bacterial disease that occurs in the betta community. It causes the fins to rag and fray, white spots around the mouth cause skin lesions, there is also cotton-like growth on the mouth, and discoloration of scales, fins, and gills of the fish. It also causes breathing problems for the fish when infected with a gill infection. These are also the symptoms of this disease.

To treat this disease, you should make sure that there is no overcrowding in the aquarium, the water quality is good, fishes are getting a good amount of oxygen. And it can be cured by treating any open wounds or fungal infections if the fish has any. You can also use Oxytetracycline and other antibiotics that have sulpha 4 TMP, TMP sulpha, or triple sulpha, in them.

20. Hemorrhagic

It is a bacterial disease that is caused by the bacteria known as yersinia ruckeri. This disease is also known as red mouth, it causes internal bleeding in the betta from its mouth and eyes. This disease is treatable thus it is not fatal.

The symptoms of this disease include signs of bleeding from the mouth or eyes.

This can be treated by disinfecting the tank. You can use antibiotics such as ampicillin to cure your fish.

21. Furunculosis

This is a bacterial disease that appears on the external part of the fish. This disease is treatable but if not cured in time, then the fish might die. this can occur when it is transmitted from an infected fish to the uninfected, under poor water and tank conditions, and under stress.

The symptoms of this disease are skin ulcers and open red sores on the tail and fins of the fish.

This disease can be treated by improving the water quality of the tank and using clear fungus as an antibiotic to treat this disease.

22. Anchor Worms

Anchor worms can be caused by a parasite attack that affects the tail or fins of the fish. This usually occurs when the water or tank is not clean, or by introducing a new fish that already has parasite eggs on it. This disease can become fatal if it is not discovered earlier. And your fish may die when not treated.

The symptoms of the disease are threads of slime coming out of the fish, and protruding worms, and when a fish is affected by this disease, the affected parts appear to be red and swollen.

You can treat this disease by cleaning the water and using antibiotics such as parasite clear and methylene blue.

23. Betta Tumors

This is a rare disease that occurs in betta. Tumors are usually cancers, growth, or cysts beneath the skin. These are caused by viral infections or genetic mutations, and they mainly affect the tail, abdomens, gills, and reproductive systems of the fish.

The symptoms of a tumor occurring in the fish are protruding scales, swelling of the body, and abnormal swimming behavior of the betta.

This tumor can be controlled by feeding the fish good quality food, treating other infections if the betta has any, and keeping good water and tank conditions are very important to prevent the disease from occurring. And keeping carcinogenic substances away from the fish and tank will also help in the prevention.

These malignant tumors are difficult to treat as some may require surgery. And the other benign tumors and cysts can be treated in several ways depending on the cause of the lump or bump.

Tips For Treating Diseases in Sick Betta Fish

Quarantine Sick Fish in a Hospital Tank

Keeping the affected fish apart from the others is the best way to prevent the disease from spreading to others. Take extra care of the isolated fish by giving it a proper diet, and try placing it somewhere quiet so it is easy for you to determine the disease. Dim the lights and add flowers and extra water décor to hide your fish and reduce its stress and anxiety. Do frequent water changes and try your best to record all the unusual behavior that your fish might be showing so that it makes it easy for you to know the reason for the disease.

Choose the Appropriate Medication for Your Betta’s Illness

Always contact the vet when you feel like something is wrong with your fish or you may not be able to identify the disease. They have the right medication for each disease and may recommend something well enough to treat your fish.

Follow Label Instructions on Medications

Don’t give medication upon your guesses and read the label before giving medicine to fish, as if you don’t do so the wrong measurement may kill your fish either under dosage or overdose.

Finish the Treatment

You need to complete the treatment. Do not stop halfway or when you see that your fish is improving, because that will stop the healing process and allow the bacteria to emerge again yet stronger this time.

The Bottom Line on 23 Betta Fish Diseases, Symptoms, and Treatment Guide

The most important of all tips is the prevention and care that you should give to your betta. Keep the water and tank clean, clean out the filter as instructed by the manufacturer, and keep a good check on their diet and behavior. And lastly, always take out some time to observe your fish for any illness because it’s always better than the disease being caught early and treatment being given at the right time.

You should always keep a first aid kit in handy with all the fish-related stuff. Sometimes when the fish is introduced to the tank it may seem stressed or anxious but it doesn’t mean that it is suffering from an illness, just give it time to adjust and after some time if you still feel that something is wrong then check for yourself or take it to the vet.