Is Swim Bladder Disease Contagious?
Swim bladder disease is the most common fish disease out there. This is medically known as positive buoyancy. Many owners of fish might be unaware of the disease, its causes, and its symptoms.
This disease is more likely a symptom of another medical issue in the fish that is affecting the swim bladder of the fish. The swim bladder is an organ inside the fish that is used to increase or decrease buoyancy, which enables the fish to maintain its depth in water. Thus, failure of this organ leads to the fish puffing and staying on the surface of the water.

According to my experience, this disease is most commonly found in goldfish. It can be due to any cause. So, here I am going to lay down all the possible causes, symptoms, and treatments for your fish from this disease so that you know what to do when it happens again.
What is Swim Bladder Disorder?
As we talked about it before, the swim bladder is an internal organ of the fish that allows it to stay beneath the water without using any extra energy to swim. This helps the fish in its buoyancy control. However, swim bladder disorder is caused by some external factor that leads to the fish having trouble swimming and they even find it difficult to control their motion underwater. This is a common complication found in any aquarium species but the most affected fish is the Goldfish and Betta.
There can be many causes of this disease such as physical abnormality, environmental reasons, and undiagnosed reasons but the most common of all is either constipation or parasites.
What causes Swim Bladder Disorder in Fish?
Coming to causes of swim bladder we know that are many. Thus, you need to find out the real cause by inspection before starting any treatment on your fish. Causes of swim bladder include:
- Physical injury
- Birth defect
- Compression from the organs
- Infection
- Floating food
- Poor quality food
- Sudden temperature changes
- Water conditions
- Swallowing air
- Old age/ genetics
Before going on and discussing all these causes, there is something that you should know.
What are Swim Bladders and their Types?
The swim bladder also known as the air bladder or gas bladder has two versions. It can be an interior portion, that is near the head of the fish. This is covered by the tissue of the tongue of fish which stops it from changing its size. Since it is attached to the spine therefore it cannot change its position.
And then there’s a rear swim bladder that is positioned behind the anterior but near the tail of the fish. This swim bladder has a thin layer of cover on it that can increase in size depending on how much gas the swim bladder holds.
Both the bladders are connected through a duct and thus can change their position due to any reason. The anterior kidney pole of the fish is located between the two bladders. So, now that we know about the interior of the fish it can help in determining the cause.
Physical Injury
Hard-impact injuries can cause trauma to the swim bladder of the fish. This disorder in fish can occur when placing the fish back into the tanks after its preservation/ maintenance. Or the swim bladder can be injured if the fish bumped itself into the hard décor inside the aquarium. This type of disorder in the bladder is not contagious and is also difficult to treat.
Birth Defect
Some fish unfortunately are born with swim bladder defects. This is again very difficult to treat as it is usually not curable. Although this is not contagious for other fishes but is hereditary which means that fish that have a natural disorder in their bladder should not be allowed to breed.
Compression from the Organs
Along with infection, compression from the organs is the most common cause of swim bladder disorder. There is interference by the compression with the function of the swim bladder that results in buoyancy problems.
This type of swim bladder disease is not contagious but it can lead to the death of the fish. This compression can occur because of:
- A fish inhaling too much air.
- Enlarged kidneys are most commonly due to cysts.
- An enlarged liver results from fatty deposits in the body.
- An enlarged stomach is usually due to too much food.
- Enlarged intestines due to constipation.
Infection
Bacterial attacks on the fish’s bladder can lead to infections in them. And parasites found in water are also another reason for such an infection. This type of swim bladder defect is contagious for other fish as well as it is water-born.
However, you can prevent an infection from emerging in the fish by keeping a good eye on the quality of water and the size of the fish on daily basis. Sometimes even if there is no infection in the fish but it can hurt its bladder by hitting an object or getting into a fight with another fish. When you suspect something in your fish you should get it treated right away as sometimes the organs are swollen and they may cause harm to the bladder.
Floating Food
The swim bladder can also be affected by floating food that fish eat. This happens when the bladder is compressed either because the fish is eating fast, eating too much, is constipated, or is gulping air when consuming food.
Poor Quality Food
Eating stale food, that is of poor quality, or is not for the fish can cause gas to emerge inside the stomach that can eventually make its way to the bladder and cause damage to it. It might even get difficult for the fish to release this gas. Sometimes flaked or freeze-dried food expands when it gets wet so which can lead to the stomach and intestines expanding.
Sudden Temperature Change
Make sure that the water temperature should be at the desired point for your fish because if the water temperature is hot then it will make it difficult for the fish to digest the food. This enlarges the gastrointestinal of the fish, which puts pressure on the fish’s swim bladder.
Having the correct tank temperature is just as important as having good water and food quality for the fish. Any changes in temperatures can have a big impact on the immune systems of the fish, whether they are in a pond, aquarium, or wild fish.
Water Conditions
You need to make sure that the tank and water are always clean to avoid any parasites or bacteria that cause swim bladder disease.
Swallowing Air
When feeding fish, it is always better to get food that sinks to the ground, or you may want to let the food rest in the water for some time before giving it to your fish. This way, when you give it to your fish it won’t hold itself to the surface of the water, which reduces the chances of the fish swallowing air.
Old Genetics
With the growing age of your fish, they become more prone to such diseases, therefore you have to monitor them closely to avoid any such problems.
What are the Signs and Symptoms of Swim Bladder Disease?
Being owners of fish, you should know of the possible diseases and their symptoms.
The most common out of all you should know by now is swim bladder disease. Therefore, it’s a must to be aware of its symptoms as well so that whenever needed you can examine your fish and start treatment right away if anything is detected.
Signs of swim bladder diseases include:
- Swimming with the tail held higher than the head
- Pinecone (scales sticking out rather than lying flat)
Curved Back
If you notice a curve at the back of your fish then there might be chances that your fish might suffer from bladder disease. You can examine that and observe your fish’s behavior, if you see a difference then get them treated.
Distended Belly
Since swim bladder disease is most commonly found in goldfish. You have to examine them closely as goldfishes mostly have rounded body shapes but if you notice anything out of the ordinary then it could be the swim bladder disease affecting the fish inside.
Lack of Appetite
You might have noticed that when dropping food how fishes swim to get it, but if you see that out of them there is one that is not showing any interest in the food then it’s a sign that something is wrong inside it.
Floating at the Top/ Sinking at the Bottom of the Tank
One of the most common signs among all is this one, you should notice and see for yourself that when trying to swim properly your fish is either floating to the top of the tank or sinking at the bottom. That’s a sign for you to take some action.
What is the Treatment for Swim Bladder Disease?
After identifying the cause and inspecting some changing behavior in your fish you know what to do next. Start its treatment as soon as possible. I would say that the prevention of swim bladder disease is better than its cure. Therefore, to avoid any such problem, make sure you follow all the below guidelines and steps.
Firstly, know what you have to look at, as when the fish has a bladder defect their organ has been compromised. Now what you need to look for in your fish are the following things:
- Swimming belly up
- Sinking to the tank floor
- The tail is higher than the head.
- Distended belly
Secondly, know that goldfish are more open to getting swim bladder disease, especially the ones with round bodies as they are prone to getting the disease. They might even have problems swimming. However, fish with longer bodies are less entitled to get the disease as their organs are more tightly packed.
Thirdly, look for any infectious signs on your fish, if you see any then further look for the following symptoms: The fish has lost its appetite, is shaking, and has clamped fins plus other symptoms of bladder disease are more visible.
Fourthly, you should thoroughly clean the water tank to prevent any bacterial attack, that causes infection in fish. And if still, the symptoms are persistent then you may want to use a broad-spectrum antibiotic from your pet store or the best thing is to take your fish to the vet for any prescription or recommendation from the doctor. You can use medicated food flakes and water treatment drops upon the recommendation of the doctor. And make sure and be very careful when giving medication to your fish, you don’t want to overdose on the fish.
Fasting on Goldfish
Swim bladder disorder may also be caused by fish overeating. When it does that it expands the fish’s internal organs like its intestine, stomach, and liver. That may cause the fish to swim improperly.
Thus, there is a three-day fast plan for fish to digest all the consumed food for those three days so that their organs shrink down to their original size. And remember not to let your fish fast for longer than 3 days. And yet even after three days, if there is no improvement in the fish then try using cooked peas.
Cooked Peas
Peas can help the fish as due to their nature of being high in fiber, they may cure constipation in fish. What you have to do is boil the peas to a point where they are soft then peel off the skin and feed it to the fish. Remember to over-boil the peas as they become difficult for the fish to eat. And do not feed more than one or two peas each day.
How do you Prevent Swim Bladder Disease?
Preventing the swim bladder is much simple and easy than you think.
Soak the Food
As you know when you pour fish food into the tank it floats on the water and thus when gulping on food the fish might also take in air, which may lead to gas in their systems. Thus, to prevent this problem soak the food beforehand so that when you add it to the tank it does not float on the surface rather the fish can easily consume it. You can purchase sinking food or feed then frozen food that is nutrient food and thawed before you feed it.
Avoid Overfeeding
Feeding too much food to the fish leads to constipation which further swells the internal organs of the fish and damages the bladder of the fish. To prevent this problem feed your fish just once a day and give it as much food that it can easily take in, in a minute or two. And do not feed the fish even if it seems as if they need it as consuming too much food is not healthy for the fish.
Clean the Tank
Cleaning the tank is also very important as if you don’t do so, then it may be affected by bacteria and parasites that cause infection to the fish’s swim bladder. Try to keep a good record of the water pH from 7.2 to 7.6.
Keep Records
Keep a record of all the behavior of your fish and if you see any behavioral changes inspect the fish closely to look for any symptoms of infection and then start its treatment.
Is Swim Bladder Disease Contagious?
Swim bladder disease is not a contagious disease itself as it is just a symptom of further diseases that the fish might get, which will be explained further down. As you already know by this time what causes this disease and the symptoms, such as fishing not eating well, gulping air, and many more.
Swim bladder disease does not occur from the fish biting or nipping each other, rather this is caused by a bacterial infection or compression of the internal organs of the fish. For example, an aquarium goldfish might have gotten the disease as a result of bacteria and infections forming inside of it. So, the disease itself is not contagious rather the bacteria and parasites living in the water lead to the spread of these diseases among all fishes.
And you know by now how to prevent your fish from getting this disease, by keeping the water clean and making sure that the tank itself is clean. Scoop out the extra food you might have thrown in as you don’t want to overfeed your fish.
Is Swim Bladder Disease Fatal?
When it comes to aquarium fish, swim bladder disease is not fatal. This may be a relief to many fish keepers with fancy fish. But being contracted such a disease is not fun for the fish. This is because it is a state of huge un-comfortableness for the fish as they can’t even swim properly and live their life the way they used to. The fish swimming with this disorder may be because of the posterior chamber being inflated. This overinflation may be because of some serious trauma to the fish as it may have cancer, infection, or might be hit somewhere.
What Happens to a Fish if its Swim Bladder is Ruptured?
If you do not treat the swim bladder on time, it may burst inside the fish which leads to the gases escaping from the fish’s body cavity, where it continues to expand further. This pressure might be so strong that it can make the stomach, and intestines out of the mouth of the fish.
The Bottom Line on Is Swim Bladder Disease Contagious?
Whether or not the disease is contagious, it isn’t, yet still, it is a nasty illness that is most common among the majority of fish. The only way this disease can be contagious is when it is caused by an infection. But there is always a precaution to a problem, you should make sure that the water keeps clean and that you’re not feeding extra food to the fish. These are some precautionary methods that you can adopt and surely you can keep your fish safe and sound.