Betta fish are hardy animals that don’t suffer illnesses as often as other species. That doesn’t mean they are immune, especially if they are living in unfit conditions. The improper quarantine of new organisms can also introduce infectious material. Plus, bettas are more likely to get sick if they’re eating a poor diet.
Bettas seem to be most prone to fin rot and swim bladder disease. Other bacterial, fungal, parasitic, and viral conditions are possible.
Figuring out what is ailing a betta is half the battle. Many bettas die because their owners misdiagnose and treat them for the wrong thing.
It’s always best to prevent sickness when possible. Keep up on regular cleanings and water changes, and don’t overfeed. Keep the water parameters at a safe level.
Hobbyists should check on their fish often. Early detection is the key to saving a sick fish.
- Parasitic Infections – Ich, Velvet, Anchor Worms.
- Bacterial Infections – Fin Rot, Columnaris, Furunculosis, Mouth Fungus, Tuberculosis.
- Fungal Infections
- Viral Infections
- Other Illnesses – Dropsy, Swim Bladder, Popeye, Hole-in-Head, Constipation, Tumors.
Parasitic Infections
Parasites often enter tanks with new fish, plants, and live food. Safe quarantine habits can prevent parasites from entering the main tank.
Some parasites do not bother bettas when they are healthy; they only manage to prey on them when they’re sick. Others, like anchor worms, can attack healthy fish.
Always follow medication instructions precisely and never stop treatment early. Most parasites have several life stages. Medications are generally only effective during certain stages. Stopping treatment early reduces the effectiveness of the medication. They are unlikely to kill the parasites unless hobbyists use them for a few weeks.
Ich (Ichthyophthirius multifiliis)
Ich is a prevalent parasitic infection caused by stress and poor water conditions.
Fish develop tiny white, salt-like dots along their bodies, fins, and gills. Initially, they may only have a few spots; fish may have dozens of spots as the parasites reproduce.
Ich is highly contagious and needs immediate treatment.
Keep the tank clean and perform daily water changes.
Velvet (Oodinium)
These parasites look like flecks of gold or rust along the fish’s body. They can often be difficult to see, and most owners notice them after examining their fish under a light. Other symptoms of velvet are usually what tell owners that something is wrong.
For example, fish suffering from this infection often rub their body along the decor. Doing so temporarily relieves their itchiness.
Velvet usually occurs due to stress, poor water quality, and too-cold temperatures. Unfortunately, velvet is highly contagious. It can be especially devastating in community tanks and sororities.
Hobbyists should treat the entire tank even if most fish appear healthy.
The best way to kill these parasites is to keep the water clean and raise the temperature to 76-81°F (24.4-27.2°C).
Anchor Worms
These parasitic crustaceans are easy to spot because they “anchor” themselves inside the fish’s skin. The ends of their bodies poke out of the skin like thin, white threads that are 2-5 mm long. The area of the body surrounding the parasite swells and becomes red.
The best way to prevent these parasites is to clean the tank and quarantine new fish.
Anchor worms are often fatal when not treated soon enough. Anti-parasitic medications are necessary to kill anchor worms.
Bacterial Infections
Bacterial infections are common because they usually occur because of poor water quality. The best way to prevent these infections is by keeping the tank clean.
Fin Rot (Pseudomonas or Aeromonas bacterial infection)
Fin rot is a bacterial infection caused by poor water quality.
The fish’s fins begin to rot, resulting in ripped and tattered fins. Their tattered fins may be black or red along the edges, and there may be blood.
Fin rot is highly treatable, especially when caught early. With proper treatment, their fins can grow back and look as they were before.
The infection is nearly always fatal if it manages to reach the body.
Treat fin rot by keeping the tank clean and performing water changes. Add aquarium salt to the water to promote healing.
Hobbyists can treat severe fin rot with antibiotics.
Columnaris (Cotton Wool Disease)
Columnaris presents along the gills and bodies as a cottony white growth. It usually attaches to the gills or mouth, causing breathing trouble. It can grow on the body if the fish has injuries.
This infection commonly occurs because of stress induced by poor water quality. It can also be a secondary infection with fish with injuries or fungal infections.
Both beneficial and harmful Columnaris bacteria are always present in a fish’s home. A healthy fish’s immune system is enough to prevent the bacteria from harming them. Unhealthy water conditions and stressful environments cause their immune system to drop. Poor immune systems leave them susceptible to infection.
Severe infections may cause damage to the gills or lesions on the body.
The best way to treat this disease is by lowering the water temperature and keeping the tank clean. Quarantine the sick fish to reduce the bioload.
Furunculosis
Open red sores and skin ulcers are characteristic of Furunculosis bacterial infections. The sores generally appear on the fish’s body, though they can also develop on the fins.
Furunculosis comes from the bacterium Aeromonas hydrophila. The bacteria is present in many freshwater aquariums. Fortunately, it rarely affects healthy fish. Fish that become sick or stressed are more likely to develop the infection.
Fish need antibiotic treatment to survive this highly fatal bacterial infection. Aquarium salt can help the healing process and reduce stress.
Mouth Fungus
Mouth fungus is a type of bacterial infection, despite what its name suggests. A white, fungus-like growth appears on the fish’s lips and mouth.
Prevent mouth fungus by keeping the tank clean and keeping up with water changes.
Hobbyists can treat the infection with antibiotics. Catching the infection early is necessary, or it will cause death.
Tuberculosis
Tuberculosis is a painful disease. The fish’s fins and tails begin to disintegrate. Eventually, they stop eating and become very lethargic.
It occurs from a bacteria called Mycobacterium marinum. The bacteria generally enter the tank from live food or untreated plants.
The possibility of betta fish developing tuberculosis is rare. Those that get this severe disease rarely live for long.
Treatment is difficult; some owners succeed with antibiotics and keeping the tank clean. Treatment doesn’t wholly cure tuberculosis, and it is likely to reoccur.
Fungal Infections
Like bacterial infections, fungal infections are common in unhealthy, dirty tanks.
Fungi are present in all aquariums and rarely affect healthy fish. Once a fish’s immune system drops, the fungus finds its way in.
These infections often go hand-in-hand with bacterial infections.
Fungal infections can occur anywhere on the body. The fungus looks like fluffy, white, cottony growths.
Fish tend to rub their bodies against decorations to relieve discomfort.
Antibiotics and anti-fungal treatment are effective in treating most fungal infections. Aquarium salt often acts as an excellent alternative to chemical medications.
Viral Infections
Viral infections are much rarer than bacterial, parasitic, and fungal infections.
Viral Hemorrhagic Septicemia (VHS)
Viral Hemorrhagic Septicemia (VHS) is another name for sepsis. It is a rare infection that generally occurs because of the piscine novirhabdovirus.
Sometimes, a bacterial infection can cause it, though this is less common.
The infection presents as red streaks along the body. It can be tough to notice on red bettas.
Sepsis often causes a secondary bacterial infection. The infection causes bleeding inside the fish’s mouth and eyes.
Fish with septicemia may develop popeye. Severe infections may result in organ failure and, eventually, dropsy.
The bacteria usually enter a tank from improper quarantining of new fish. It may also enter a tank from contaminated live food.
Septicemia is sometimes confused with nitrite poisoning. Poisoning also causes red streaks along the body. Test the water before treating for septicemia to rule out nitrite poisoning.
Other Illnesses
Some illnesses and conditions do not fall into the “infection” category. Infections often prompt them, though.
Dropsy (Edema)
Dropsy refers to the swelling of a fish’s body and the pineconing of a fish’s scales. Specifically, the liver and kidney swell because of fluid buildup.
Pineconing refers to the scales sticking outward from the body. The scales make the fish look like a pinecone when viewed from above.
Many things can cause dropsy, including viral, bacterial, and parasitic infections. It can result from poor nutrition and is more common in fish that eat live foods.
A fish usually develops dropsy after their illness has severely progressed. It is the last step before a fish dies.
Unfortunately, dropsy is almost always fatal. Hobbyists may be able to save their fish with quick action and effective treatment.
Betta Fish Swim Bladder Disease
Swim bladder disease is easy to spot. Fish have trouble swimming and regulating their buoyancy. Many swim on their sides or get stuck at the top or bottom of their tank.
The swim bladder is an organ that fish use to control their buoyancy. It allows them to move up and down in the water column.
Swim bladder problems are prevalent amongst betta fish, often due to overfeeding. Fish may also develop swim bladder issues from bacterial infections or their genetics.
Many inexperienced owners aren’t sure how to cure swim bladder disease in betta fish. They mistakenly feed bettas peas. Goldfish with swimbladder issues can get better by eating peas. Bettas can’t digest plant matter.
Hobbyists can fast their betta for two or three days until they pass all their food.
Another option is to feed them a small amount of daphnia. Daphnia works like peas for goldfish. It helps them to pass the excess food they’ve consumed quickly.
Popeye
Popeye is easy to spot because the fish’s eye(s) will swell and bulge from its head.
It most commonly occurs from living in dirty conditions for too long. It can sometimes be a symptom of fish tuberculosis.
Popeye is almost always a secondary symptom. It is indicative of a more serious disease or infection.
Popeye that goes too long without treatment can cause blindness.
Keep the water conditions clean and healthy to prevent and treat popeye.
Hole-in-Head
Fish may develop small holes or lesions above their eyes from hole-in-head disease.
Initially, the holes are usually small, the size of a pin. As the condition progresses, the holes get increasingly larger. Although the holes begin on the head, they develop down the fish’s lateral line.
The exact cause of this condition is unknown. Some theories say that fish are more likely to develop it if they live in unsuitable conditions. Others say a lack of nutrients is the problem.
A positive link exists between hole-in-head disease and the parasite Hexamitiasis. Researchers say that the parasites often cause hole-in-head disease. As a result, the fish often get secondary bacterial or fungal infections.
Prevent and treat this problem by feeding healthy foods and keeping the tank clean.
Hole-in-head is easy to treat when caught early; it’s often fatal if it progresses too long.
Constipation
Bettas commonly experience constipation from overfeeding or eating nutritionally-deficient foods.
Constipation is one of the most common causes of swimbladder disease.
Hobbyists can treat constipation like swim bladder disease by fasting or feeding daphnia. Fast the fish for about two to three days to let the food exit the system. Or, provide a small amount of daphnia to help their digestion move along.
Prevent constipation by feeding high-quality, high-protein foods, and do not overfeed.
Tumors
Tumors are common among bettas and can develop anywhere along the body. They are most common near the gills, tail, abdomen, and reproductive organs.
Tumors may be cancerous, or they may simply be cysts, bumps, or benign growths.
There is no way to treat tumors other than through surgery. Surgery is often impractical and unsuccessful in tiny fish like bettas.
Hobbyists simply must keep their fish comfortable. It may be possible to slow down tumor growth by keeping the tank clean and feeding healthy foods.
While tumors are always fatal, they do not always cause a fast death. Many fish can live happily for several months after developing a tumor. Hobbyists must watch their fish for any signs of suffering and decide the best course of action.
Summary Of Conditions & Treatments
| Infection/Condition | Type | Treatment | Medication |
| Ich | Parasitic | Improve water quality | Medications containing:
OR
|
| Velvet | Parasitic | Raise water temperatures & improve water quality |
|
| Anchor Worms | Parasitic | Remove them with tweezers & improve water quality |
|
| Fin Rot | Bacterial | Improve water quality & add aquarium salt to reduce stress |
|
| Columnaris | Bacterial | Lower water temperature & improve water quality |
|
| Furunculosis | Bacterial | Add iodine to remove the bacteria & add aquarium salt to reduce stress |
|
| Mouth Fungus | Bacterial | Improve water quality |
|
| Tuberculosis | Bacterial | Improve water quality | N/A |
| Fungal Infections | Fungal | Increase the water temperature & add aquarium salt to reduce stress |
|
| VHS | Viral | Improve water quality |
|
| Dropsy | Varies | Improve water quality & add aquarium salt |
|
| Swim Bladder Disease | Bloating | Fasting or feeding daphnia | N/A |
| Popeye | Varies | Improve water quality |
|
| Hole In Head | Parasitic (Sometimes) | Improve water quality & feed healthy foods |
|
| Constipation | Overfeeding | Fasting or feeding daphnia | N/A |
| Tumors | Growth | Surgery (not recommended) | N/A |
* These medications are toxic to many kinds of sensitive fish & invertebrates. Read all the directions & precautions on the label & use them with caution
