Betta Fish is Dying

How Can You Tell if Your Betta Fish is Dying?

The last part of every life is death, and death can come quite suddenly in certain cases. However, if your betta is dying from simple old age, you will be able to see warning signs for months in advance. Betta fish live for 2-7 years (bettas from breeders live much longer than store bought bettas that are damaged by ammonia and nitrite in small cups), so being aware of when your pet may pass is helpful. After spending 5 or more years with your little buddy, sudden death can be devastating.

Betta fish exhibit signs that they are dying from old age, most notably color loss and lethargy. Other symptoms are also possible, and more than old age can kill a betta. Some diseases are almost always, or always, fatal, so we will cover some of the warning signs of those diseases in addition to the warning signs of old age.

In this article, we will cover lethargy, fading color, hunched back, dropsy, laying down, frequent breathing, decreased appetite, slow reactions, nitrite poisoning, and fish TB.


Lethargy is normally the first sign that something is wrong with your betta. It is commonly seen if there is an issue with ammonia, nitrite, nitrate, temperature, illness, or old age. If your betta is acting lazier than normal, this does not point to one issue, in particular, so you will not be able to give your betta a diagnosis without more symptoms.

A lethargic betta acts very tiredly and sadly most of the time. They will hang out at the bottom of the tank, swim less, and will be less interested in food. It is also common to see a loss of color in conjunction with this condition.

You should also be on the lookout for depression, as betta fish can suffer from this. There aren’t any medications that can treat this condition, but extra stimulation can help improve this condition. However, fish depression is very rare when compared to simple lethargy.

Fading Color

If your betta is suddenly losing color, this is more concerning than your fish just being lethargic. If the color change is significant, there is a good chance that your betta is seriously ill. On the other hand, if it is a slight dulling, your betta could be old, or if the scales are changing to a different color, it could just be the marble gene.

The marble gene causes a random color change in bettas at any point in their life. It sometimes changes them lighter, sometimes it changes them darker. Older bettas tend to “gray” by fading to a slightly lighter color, and the change is often so slow that you won’t notice until you look back at old pictures.

A significant color change could point to severe illness and is a bad sign. Of course, if a color change is the only symptom, you may not be able to pinpoint the problem at first. Test your water, if there is an issue with your parameters, you need to take immediate action through water changes.

Hunched Back

Old bettas tend to develop a slight, or significant, hunch in their back. This is normal as they age, for both male and female bettas. However, if your betta also develops a skinny stomach and starts to lose weight, you should look at both fish TB and internal parasites as possible causes.


Dropsy is not a symptom of aging, but rather is a symptom of kidney failure. As you may guess, healing any major organ failure in a fish is extremely difficult and often impossible. This is one of those illnesses that is almost always fatal.

There are five main causes of dropsy, and only one is truly treatable, but it is very difficult to treat. Less than 90% of fish affected by this condition will live, so most choose to put their fish out of any additional pain instead of attempting to treat the condition.

Dropsy is characterized by extreme swelling in a fish accompanied by pine coning scales. As the kidney fails, fluid builds up in the fish’s body and causes it to swell. Kidney failure can be caused by a fungus, bacterium, injury, age, or parasite.

The bacterial infection is the only treatable type of kidney failure in fish and is treated with Kanaplex and unscented Epsom salts. You should start with a very large water change, upwards of 50%. You should then add 1 tbsp of Epsom salt per 5 gallons of water and begin to dose Kanaplex.

Laying Down

If your betta is resting on the bottom of the tank but remains upright, he or she is probably just resting. However, if you notice them resting more often than normal, it could be lethargy. On the other hand, if your betta is lying down horizontally on the substrate, something is wrong.

A betta that is lying flat on the substrate is sick betta and this is a very bad sign. If it is caused by disease or old age, your betta will likely not live much longer. If the cause is terrible water quality, there is a chance that your betta will make it if you do three very large water changes in 24 hours and keep ammonia and nitrite at 0 and nitrates less than 10 for the following weeks.

Frequent Breathing

Rapid breathing is similar to lethargy in that it is a symptom that something is wrong, but it is nonspecific. This symptom is not a death sentence but generally an early warning sign that your fish is sick or old.

Sick fish, fish in very bad water, and some old fish will all breathe faster than normal. For old fish, it will be a gradual change that you may not notice until you compare your older fish to a younger one.

For sick fish and fish in bad water, the symptom will have a rapid onset of just one or two days, or in extreme cases, just a few hours. Always test your water parameters first and check your temperature before assuming your fish are sick.

In addition, if you notice your fish is taking atmospheric air more often than normal, this is usually a water quality issue. More often than not, there will be some ammonia or nitrite suffocating or burning your fish, forcing it to use its labyrinth organ more than normal.

It is also possible that there is very little dissolved oxygen in the aquarium. Try to increase the oxygen by adding live plants, a bubbler, or a waterfall filter. In most cases, bettas will be fine in water with slightly less oxygen, but if they have any other tank mates, even snails, the tank mates will suffer and potentially die.

Decreased Appetite

A decreased appetite is a normal symptom of old age. As a betta grows older, its metabolism slows down, so it simply does not need as much food as it once did. If the temperature is lower than normal, this can cause the same effect on a healthy betta.

Severely sick bettas will also have decreased or nonexistent appetites. For older betta, the change is gradual over weeks or months, but for sick betta, the change will be much faster, normally in just a week.

Slow Reactions

Slowed reactions are common in bettas with lower metabolisms or with eye issues. If your betta swims away slower or takes longer to react to food and other objects in the tank, it could simply be getting older. Most sick fish still have a good reaction time, unless they are unable to move. Old bettas will still be able to move away from potential threats, but it will take longer for them to recognize the threat and to get away.

Nitrite Poisoning

Nitrite poisoning is a serious issue in cycling tanks or tanks that are undergoing a mini-cycle. Spikes in the nitrite levels often kill fish, and there are warning signs that the fish is doomed. If the fish is exposed to severely high nitrite levels and has a red belly, there is nothing more you can do for it and euthanization is the kindest option.

You can use methylene blue to treat nitrite poisoning that is not as severe. If your fish got nitrite poisoning, it will have long term consequences and shorten the fish’s life span.

Fish TB

Fish TB is not similar to human TB in terms of symptoms, but it is zoonotic, which means you can catch it from your fish. Instead of causing severe lung issues, it will appear as a rash that antibiotics can easily treat but it can have devastating side effects. Always use gloves when dealing with a tank infected with TB.

Fish TB is characterized by two of its most common symptoms; curved spines and lesions on the skin. This illness has no cure and can stay dormant for over a year, so you must euthanize any fish that came in contact with an infected fish or any fish that came in contact with water from an affected fish.

If the spine curves drastically downward or two the side and the fish has lesions, chances are it is TB. Since there is no cure, it is a sure sign that your fish will die. Luckily, it is rare in bettas, but not unheard of.

In conclusion, there are many symptoms that your betta is aging, such as decreased appetite, a hunched back, slow reactions, and lethargy. However, these symptoms can also be symptoms of illnesses or poor water quality, so you must be alert for these as well. In addition, if your fish develops pine coning scales or a bent back with lesions on the skin, euthanization is normally the best option for these afflictions.

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