10 Signs of a Sick Betta Fish and What To Do 

Updated April 7, 2022
sick orange betta fish

Do you know how to spot a sick betta fish? If you see your pet struggling to swim, looking bloated, or with deteriorating fins, these could all be signs of betta fish sickness. Learn the most common symptoms to help you identify possible fish ailments and get the treatment your betta needs to recover.

Signs of a Sick Betta Fish

Unfortunately, symptoms of sickness could point to a number of betta fish diseases. Most bettas will display one or more of the following signs when they are ill. Use these symptoms to help determine if your pet's health is suffering.

Not Eating

Bettas have very healthy appetites, so one of the first indicators a fish has an illness is when they show no interest in food. This is why it's so important to watch your fish when you feed them and make sure they eat. If they refuse food for more than one meal, examine them a little closer to see if you notice any other signs of potential illness. It's possible your betta could be constipated, or may be responding to poor water quality or stress.

Lethargy

lethargic sick betta fish

Betta fish can be very active, but they do stop and take time to rest and even sleep. Because of this, it may not be immediately apparent to you that your betta is less active than usual until some time has passed. Monitor your fish closely to note any changes in their activity level.

Bettas are curious and territorial creatures, so if your pet stops investigating their surroundings for any significant amount of time, they may be ill. Additional indicators that your fish is lethargic are floating aimlessly at the top of the tank with their mouth at the water's surface, settling into a secluded spot at the bottom of the tank, and showing no interest in anything going on around them.

Keep in mind that bettas do sometimes rest or remain immobile even at the surface, as they can breathe air through a special organ called the labyrinth. This does not necessarily indicate they are sick. The key is to have a frame of reference and compare their current activity level to their typical behavior. Is your fish indifferent to your presence, ignoring their food, or do they otherwise appear "off"? These are the signs of lethargy you need to watch for.

Looking Skinny

Some fish begin to look like they are wasting away even if they haven't gone off their food. A skinny betta's body will typically appear concave on their sides. This could be a sign that your pet's current diet is lacking in important nutrients or you may be underfeeding them.

Most hobbyists recommend offering bettas a varied diet that includes a mix of staples, such as betta pellets and high-quality flake food, supplemented with fresh or frozen brine shrimp, and freeze-dried bloodworms. Ensure your betta is eating a balanced diet and you're offering them an adequate volume; many owners fear causing bloat due to overfeeding, but underfeeding is generally more concerning.

Appropriate live foods, such as brine shrimp and daphnia, are excellent for bettas, but finding a quality source can be difficult. Also, be aware that feeding live foods comes with the risk of introducing parasites or other diseases to your fish. If you are treating a sick betta, it is best to avoid offering live foods unless you are sure of their quality and safety.

Trouble Swimming

Some diseases interfere with a betta's ability to swim normally. The swim bladder is a structure that allows a fish to control their buoyancy. If the swim bladder becomes infected or injured, your fish could have trouble swimming.

Other causes of swim bladder disease (SBD) in bettas are poor water conditions, low water temperature, stress, and overeating. Sick betta fish with SBD may struggle to swim up or down, swim on their side or upside down, or swim in circles. Swim bladder problems are generally treatable; depending on the cause, your betta might need antibiotics formulated to treat fish.

White Spots or Film

Parasitic and fungal diseases typically leave some sort of evidence on the fish. If you notice any odd material that looks like cotton clinging to your betta, they likely have an infection like ich, columnaris (also known as "cotton wool" or "cotton mouth"), or velvet.

Areas of thick mucus, a film over the skin, or itching on objects in their habitat are other signs of these conditions. These infections can be fatal if left untreated, so appropriate water treatments should be used. Minimizing your betta's stress and performing daily water changes are necessary during the healing period.

When you are treating a betta for a parasitic or fungal infection, it may be necessary to move the betta to a temporary hospital tank setup, especially if your betta lives with tankmates. Using a hospital tank allows you to isolate your fish in a clean, safe environment with appropriate water quality, and treat your fish's main aquarium without having to worry about harming other fish or invertebrates.

Fin and Tail Deterioration

Bettas tend to clamp their fins when they don't feel well. Beyond that, fins that begin to look frayed or appear as if they are being eaten away may indicate your fish has fin rot infection. Fin rot begins with mild signs, but as the disease progresses, your betta's fins will look increasingly ragged. You may notice their color begin to fade or holes appearing in the fins.

This damage to the fins and tail is generally a result of poor water quality. Both fungal and bacterial infections can cause fin rot in fish, and there is no single cause of this condition. Bacteria in the water eat away at the fins to create a ragged appearance. These bacteria are not transmissible to humans.

If you notice these symptoms, know that it's a common condition and is treatable if addressed in the early stages. The first step is to remove your betta from their primary aquarium and place them in a quarantine hospital setup. This step may not be necessary if there are no plants or other animals in your betta's main setup, but it doesn't hurt to remove your betta to keep them comfortable while you address the water quality issues in the main system.

You can use aquarium salt to help treat fin rot in bettas. Select an aquarium salt intended for medicinal usage in freshwater systems, and treat per the directions on the label. Do not use aquarium salt as a treatment for more than 10 days at a time. Aquarium salt typically helps with mild to moderate cases of fin rot, but it may not help with more advanced cases.

Medicines like tetracycline are available to help betta fish suffering from fin rot. Fungal infections are unlikely to respond to this treatment, however. Depending on the cause of fin rot, you may need to try different combinations of medications.

Melafix and Bettafix are popular treatments for fin rot that contain an antimicrobial active ingredient, but these are not always safe to use as treatment for bettas. There is a risk a betta may die from exposure to the active ingredients found in these products. MelaFix has a higher concentration of the active ingredient, melaleuca extract (tea tree oil), so avoid it in favor of BettaFix. Follow all manufacturer warnings, dosing levels, and treatment protocols. Also, consider the danger to your fish. You may only want to treat your pet with this product in severe cases of fin rot, where other treatments have failed.

If you prefer to try an all-natural option, you can add a single Indian almond leaf to your betta's aquarium and perform careful water changes. The leaf will reduce water pH slightly, so monitor it to make sure it doesn't go too low, but with regular water changes, this shouldn't be an issue. In cases of mild fin rot, this may just do the trick.

Bloating

If your betta's body suddenly looks puffed up or swollen, this is a sign of sickness. It could be indicative of constipation, but it could also be sign of a condition called dropsy, which can be life-threatening. With dropsy, the entire fish swells up, and the scales stand out a bit from the body. It is caused by a bacterial infection in the tank, so antibiotic medications are necessary. You may need to set up a hospital tank for your betta, as well, perform appropriate water changes, and administer an antibiotic that is safe for bettas.

Lack of Feces

Sick betta fish generally do not have normal bowel movements, so if your betta is not pooping or has stringy feces, this could be a sign of sickness. It's possible they could be constipated, underfed, ill, and simply not eating enough. Examine your fish to see if they show any other signs of sickness. Constipated bettas can often show many of the above signs like a bloated abdomen, trouble swimming, lethargy, and a low appetite.

Swollen Eye

Swelling of a betta's eye is often referred to as betta fish popeye. This condition can be caused by bacteria, fungal, or parasitic infection, or may result from physical trauma to the eye. Most of the time, an injury will lead to only one eye being swollen, whereas swelling of both eyes typically indicates an infection. Treatment will depend on the cause, but popeye can be successfully cured with early action.

Loss of Color

When a betta's color fades or they appear to be losing color, this can sometimes point to sickness. You should consider a few factors when deciding if this is a sign of illness. A betta's color can fade when they become stressed. This alone isn't cause for concern, but stress can make a fish vulnerable to infections or other ailments. It's also possible the color loss could be due to old age or injury to the scales. However, if you notice other signs of sickness in addition to the loss of color, it's important to begin treatment.

General Steps to Prevent and Treat an Ill Betta

Once you've noted any specific signs of illness your betta shows, it's time to determine which disease or condition could be making them sick. You can compare the symptoms to a variety of the most common betta diseases, but if you're still not sure what's wrong, give your local aquarium shop a call and describe what you see. Someone on the staff may be able to hazard an educated guess about what your fish has and recommend a specific treatment that can help. There are also exotic pet vets who have specialized knowledge in fish medicine.

However, many hobbyists forgo more aggressive measures when treating their bettas. The most important thing you can do is check and maintain your betta's water quality on a weekly basis, perform water changes of roughly 20 to 25 percent of tank volume every week, and thoroughly clean your betta setup on a monthly basis. This involves vacuuming the aquarium substrate to remove uneaten food and fish waste, and performing a water change with treated tap water or appropriate fresh water.

Setting up a hospital tank is another excellent option, especially if your fish is suffering from some sort of infection, and there are plants or other tankmates in the primary aquarium. This does not need to be permanent. Use the hospital tank as a place to quarantine your fish in ideal water conditions while you administer any medications or treatments and clean the main system.

Prevention is always preferable to treatment after a disease is present. Follow the guidelines for each illness if your fish is showing symptoms of serious illness. However, by monitoring your fish on a daily basis, attending to tank maintenance and water quality, and avoiding the introduction of parasites and other infectious agents, you can effectively give your betta the gift of lifelong health. Bettas are famously hardy, resilient fish, and with adequate care, your betta will give you years of enjoyment.

Listen to Your Gut

Remember, the time you spend observing your betta fish means you know them better than anyone. If your gut tells you something isn't quite right, it's probably true. Trust your instincts, try to note as many symptoms as you can, and get your fish the treatment they need as quickly as you can to keep them happy and healthy.

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10 Signs of a Sick Betta Fish and What To Do