Betta Fish Diseases

Betta Fish Diseases, Prevention, and Care

Just like other living things Betta fish can fall for certain diseases. However, these diseases can be prevented or treated as well. Therefore, you need to look out for symptoms on your Bettas to know when they are down with diseases.

What are the Betta fish diseases? Common diseases affecting Betta fish are Ich, Dropsy, Fin Rot, and Velvet. The causes of these diseases are bacteria, fungi, and parasites. You can prevent these common Betta fish diseases through regular water changes, good feeding routine, and ensuring clean environment. If unfortunately your Betta is already down with diseases, applying recommended treatment care or letting a trained veterinarian take over is the best thing to do.

Knowing more about Betta fish will help in understanding the nature of diseases that can affect them, and the necessary preventive measures to apply. Also, it helps in knowing the right steps to take to care for your sick Betta.


  • Things to Know about Betta Fish
  • Diseases in Betta Fish and Recommended Treatment
  • Basic Preventive Care

Things to Know about Betta Fish

The History of Betta Fish

Betta fish also goes by the name of Siamese Fighting Fish. They originated in the land of Siam, what is modern-day Thailand. People from the region have kept betta fish as pets for over 150 years. Betta fish are actually a very diverse family of fish. There are some 70+known species of Betta fish. While we are most familiar with the brilliantly colored variety, betta fish come in all shapes, sizes, and colors.

Betta Fish in the Wild

One can still find wild betta fish. Brightly colored, frilly fish are not be found in the wild. Wild betta fish is a dullish gray color and tend to have short, stubby tails. Long, elegant tail fins are one of the most defining features of the family of betta fish we all know and love.

Beginnings of Domestication

Betta fish often live in puddles of stagnant water, like rice paddies. There is a historical record of children gathering wild bettas to fight in the waters of rice paddies. Bettas are well-known for being aggressive and highly territorial, hence the moniker Siamese Fighting Fish. It wasn’t long before these fish battles attracted a wider audience and rose in popularity.

The State and the Betta Fish

The Siamese King could not help but notice the popularity and abundance of the new sport of betta fish fighting. As it was such a hugely popular activity, he decided that he would regulate and tax it. This gave it an air of legitimacy and also saw the further spreading of betta fish fighting as a spectator sport.

There are many who oppose the fighting of betta fish. This practice is very stressful on the fish. Often, one or both of the fish die in the ensuing battle. Fighting isn’t a game to the fish, it is a real territorial dispute. Male fish placed together will almost always fight, though female fish will also fight. In fact, you shouldn’t even keep a male and female in the same tank except for breeding purposes.

The Spread of the Betta to the West

In the late 1800s, the King of Siam gave some betta fish to a Danish scientist as a gift. The scientist, Theodor Cantor, took the fish home and studied them. He bred them and studied them more. This lead to the publication of a scientific paper and a classification of the fish as a new species. Betta Speldens, or “beautiful warrior” is the scientific name for the betta fish.

Importation began shortly after the scientific classification, first in France and then other places in Europe. In the first decade of the 20th century, betta fish were imported to the United States for the first time.

Biology of the Betta Fish

Betta fish can be found all over southeast Asia. They live in a unique habitat and prefer slow moving streams and even puddles of stagnant water. Betta fish need an oxygen-rich environment to survive in. The fish prefer warmer water. But can survive for a brief time in colder water. Referred to as anabantoids, betta fish are unique among fish species.

Do Betta Fish Have Lungs?

Betta fish breathe oxygen, which has to lead many to the assumption that they have lungs. They have an organ called a labyrinth. This is an ancient organ that allows the fish to breathe oxygen. Betta fish do also have gills as well. The labyrinth helps transmit oxygen to the bloodstream, allowing the fish to live outside of water briefly. This organ is also how they can live in water with such a low oxygen concentration that would kill most other fish.

Diseases in Betta Fish and Recommended Treatment

Though the betta fish is a hardy species, it is not invisible. There are many common diseases that betta fish may suffer from. Many of these problems are preventable with good care and preventative measures. Like all animals, a betta fish needs space to move around. While they can live in small spaces, they do prefer to have a bit of room for movement and activity. They also require a clean environment. That means regular water changing and cleaning of their habitat.

Failing to do this will almost guarantee that your betta will get sick. However, even when one takes all the precautions in the world, your betta will still likely get sick on occasion.

Fin and Tail Rot

This is one of the most common diseases that domesticated betta fish will suffer. Most often caused by fungi or bacteria, the disease attacks, as the name implies, the fins and/or tail. This can be prevented by regularly cleaning the fish tank. While it can be a fatal disease, if caught early and properly treated, fin and tail rot is curable. The use of antibiotic medicated water drops is the most common treatment for this condition.


This is another common, but treatable, bacterial infection that betta fish often suffer from. Regular disinfection of the fish tank is a great way to prevent the growth of this bacteria. However, this disease, when caught early, is rarely fatal. When present, hemorrhagic results in bleeding in the mouth and eyes of the fish. You will be able to see red pockets near the eyes or mouth. Treatment usually consists of a multi-day course of antibiotic water drop treatment.


This is a rare but incredibly serious and most often fatal disease in betta fish. It is a severe infection in the liver of the fish. Outward symptoms include a swollen abdomen, sunken eyes, and scale abnormalities. Unfortunately, there is no known cure for dropsy and it is often fatal for betta fish. It is most readily prevented through regular cleanings and ensuring that the betta has a varied nutrient-rich diet. A medication called Betta Revive has shown promise at helping to treat dropsy, but it doesn’t cure the disease.

Pop Eye

As the name implies, this is a disease that affects the eyes of the fish. The most obvious symptom of the disease is swollen eyes. The condition is most often caused by a viral infection or a tumor. Fortunately, this disease is not often fatal in betta fish when caught and properly treated. Antibiotics like Tetracycline can easily clear up this infection. Once the fish is no longer suffering from the condition, it is recommended to do a full water change.


This is a betta fish disease that often attacks both the tail and fins, as well as the scales of the fish. It is a bacterial infection and often, the most noticeable symptom will be the tearing and fraying of the fins of the fish. It can also cause a scale discoloration, lesions, and even growths on the mouth. Because it often attacks the gills, it can cause breathing difficulties. The lesions, if not treated, can also become infected.

It can be prevented with regular water changes as well as the treatment of any wounds or skin issues you might notice on the fish. Though columnaris is treatable, a betta fish can die in as little as 72-hours if you fail to properly treat the condition. The disease is treated through the use of a course of antibiotics.


This disease is a skin condition that most often affects betta fish in dirty tanks. This is a parasitic disease that is the most noticeable change of the scales of the fish to a rusty orange color. If you have other fish in the tank with the betta, it is even more imperative that you treat this quickly as it is highly contagious. It can easily be treated with medicated water drops such as Bettafix Remedy and other similar medications. Though this disease is treatable, the betta can die from velvet in just a matter of days if left untreated.

Ich or Ick

This disease goes by either name noted above. It is also known as White Spot, giving a good indication of the symptoms of this disease. This is a fairly common disease in betta fish that can easily be treated with Malachite Green or Fish-zole. This condition can be prevented with regular water changes and cleaning of accessories and gravel.

Anchor Worms

This is another parasitic disease that many betta fish suffer from. The infected part of the fish will appear red and swollen. You will also see actual worms and threads of slimy substances oozing out of the affected area. Good water care practices go a long way towards preventing this condition. Parasite Clear or Methylene Blue can treat anchor worms. It is rarely fatal unless left untreated for an extended period of time.

Basic Preventive Care

The best offense, they say, is a good defense. This means that staying on top of fish care is the best way to help ensure that your fish doesn’t get sick as much as possible. The best way to do this is to provide a good environment and have a regular plan for cleaning your fish tank and using preventative treatments. Though not recommended, a betta can live in a space as small as a single gallon fish bowl. Most recommend a five gallon tank.

Water Conditions

Many recommend that you change your betta’s water about once every two weeks. This helps to ensure that they always have a fresh and clean environment. Betta fish prefer warmer water, so using water straight out of the tap to change replenish their tank can cause undue stress on the fish. You can purchase specially-formulated water, or alternatively, fill clean gallon jugs with water and leave them out for 24 hours to allow it to stagnate and get to room temperature.

Note on Water Changes

Many people do partial changes bi-weekly and a full change once a month. This is adequate for keeping water conditions clean. If this is your preferred method of cleaning, be sure to give any gravel and tank accessories a thorough rinsing before returning the fish to the tank.

Back to the Water Conditions

By doing this, you are providing an ideal environment for the fish, most similar to what they would have in their natural habitat. You also want to make sure that you place their tank in a temperature stable area. Avoid placing the bowl near vents, windows, or doorways. Betta fish do not tolerate dramatic temperature changes well.

It is vital to rinse all accessories before placing them in the betta tank to remove all contaminants. You shouldn’t use heaters, water filters, or aerators in a betta fish tank.

Feeding Your Betta

You not only have to ensure that you buy food specially designed for betta fish, but also not to overfeed them as well. Betta fish require specially-formulated diets and fare very well on pellet style food designed for their exacting needs. It is best to feed the betta multiple times, but just a little per feeding. Otherwise, the food will swell up and muck up the water. When using premade betta food pellets, you usually feed them about 6 pellets a day. You can also give your betta freeze dried brine shrimp or bloodworms as a treat if you like.

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