Skip to Content

3 Common Causes of Oscar Fish Swim Bladder Disease

3 Common Causes of Oscar Fish Swim Bladder Disease

Share this post:

This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Oscar fish are among the most loved cichlids that you can buy. If you already own Oscars, you know how neat they are.

These are big fish that many people think are excellent pet fish. Overall, they’re a lot of fun to care for.

When your fish starts acting funny in the tank, you’re going to be worried. Has your Oscar started swimming upside down?

Sometimes Oscars might get swim bladder disease. This will cause them to swim in unusual ways.

What causes swim bladder disease and what do you need to do to protect your fish? Read on to learn more about this situation so you’ll know what to do.

What is Swim Bladder Disease?

Swim bladder disease is a condition where the swim bladder malfunctions. Many types of fish have swim bladders.

The swim bladder is an organ that controls buoyancy and allows fish to swim properly. When this organ malfunctions, it makes it difficult for fish to swim around as normal.

The Swim Bladder of a Fish
The Swim Bladder of a Fish

This organ is a gas-filled sac that inflates and deflates to control buoyancy. Sometimes something might occur that will prevent the swim bladder from working as intended.

It can make it very hard for fish to get around. Sometimes fish might only be able to swim upside down or sideways.

You’ll sometimes see fish barely swim at all since they can’t control their movement properly. It can be difficult for fish that have this disease because it makes it tough to eat or get away from bully fish.

What Causes Swim Bladder Disease?

So what causes swim bladder disease to happen? Is this some type of traditional illness or is there another cause?

Below, you’ll learn about several things that can cause swim bladder issues. This should help you to understand what you need to do.

1 – Constipation

The most common cause of swim bladder issues is constipation. When a fish becomes constipated it’s going to cause its belly to swell.

A swollen belly is going to press against the swim bladder. Since the swim bladder needs to inflate and deflate to function, it’s not going to work if it’s being compressed by a swollen belly.

Feeding your fish too much at once will cause this to happen. This is why you need to be careful to only feed your fish just as much as you’re supposed to.

You can keep this from happening by feeding your fish carefully. It’s possible to fix this issue by clearing up the constipation.

Feed the Oscar fish boiled peas to encourage easier defecation. The constipation will be alleviated and the fish should be able to swim normally again.

2 – Infection

An infection might cause swim bladder issues, too. Sometimes an infection of the intestinal tract will cause swelling in that area.

It’ll make it hard for the fish to swim normally due to the swim bladder being compressed. In many ways, this is similar to the constipation issue.

There’s simply a different cause for the swelling. Fish can become infected for many reasons, but it’s more likely that stressed fish will get infected.

Clear up the intestinal infection and things should get better. Feeding the fish some food that has been treated with antibiotic medication can help.

You can also treat the fish with antibiotics in other ways. Treating the water is an option.

After the infection goes away, the swim bladder issues should be resolved. You want to deal with infection problems as soon as you can.

3 – Injury

Oscar in Community Tank

Physical injuries can cause swim bladder problems, too. This can make it so the swim bladder won’t work as intended.

A fish could have been injured while fighting another fish. It also could have rammed into an object in the fish tank.

You might have injured the fish yourself while handling it, too. Occasionally a fish can be harmed when being transferred to a different tank by its owner.

The swim bladder issue should be resolved once the injury heals. However, there are times when an injury will be permanent.

Permanent injuries might cause the swim bladder problems to be permanent as well. Sometimes fish owners will choose to get a fish euthanized when the swim bladder issues won’t resolve.

A fish with serious swim bladder problems will have a significantly decreased quality of life. You can discuss this issue with an exotic veterinarian if you want advice.

Be Careful When Feeding Oscar Fish

Oscar Fish Feeding

When feeding Oscar fish, it’s easy to feed them a bit too much. These fish don’t necessarily know when they need to stop eating.

If you just keep feeding the fish, they’re going to keep eating. Cichlids are fish that love to eat, and Oscars are some of the largest cichlids you can own in a home aquarium.

Many people have a tough time when they feed Oscars one large meal per day. This makes it easier for the fish to eat too much at once and become constipated.

Instead, you should feed Oscars three times per day. Feed them smaller meals so that they won’t have problems with constipation.

Final Thoughts

Now you know a lot more about swim bladder issues. Swim bladder disease has the potential to be a rather annoying issue.

If you don’t solve these problems, it might be hard for the fish to keep going on. Fish have a tough time eating when they can’t swim normally and they might also get bullied by other fish.

A common cause of swim bladder issues in your Oscars is constipation. If that’s the case, you can fix things by feeding the fish boiled peas to encourage easier defecation.

Other than that, you might need to look into whether the fish are infected or not. An intestinal infection can cause swim bladder issues due to swelling.

Antibiotics can solve this issue and get things back to normal. Problems with physical injuries might also be to blame.

Swim bladder problems are one of several illnesses that Oscars have to deal with. Do your best to troubleshoot and figure out what is causing it.

Unless the fish has been permanently injured, it should get better and start swimming normally again.

Share this post:

Eddie Lawrence

Friday 29th of July 2022

I would like to know more about Oscars I have two Oscars and a 75 gallon tank one right now is swimming in a 45° bed how can I take care of it she swims a little but acts like she's dead and she's not thank you


Friday 29th of July 2022

A couple of things to consider are whether anything has changed recently (tank mates, water conditions, etc.) and whether or not this behavior is sudden or ongoing. I have quite a few posts about Oscars on this site that you can check out to learn more about them. You can check out all of those posts here: or a specific post about Oscars acting lethargic here:

I hope that helps!