Can Fish Have Strokes? The Correct Answer Is Here!

If you are a newbie to aquatics, you will feel extremely worried if your pet has serious health problems. Have you ever wondered, “Can fish have strokes?” 

Many aquarists have this same question. It may seem like a silly question, but it is a valid one. Today, we’ll help you clear this query with valuable information.

Let’s check it out!

Can Fish Have Strokes?

Fish can have a stroke, but it is very rare.

The short answer is yes. Fish have many organs, including a brain. Strokes happen in the brain of an animal, so, technically, a fish can have a stroke.

However, this is highly unlikely! There have been no or few reported cases of a fish having a stroke. 

A stroke in a fish is not common, and there is no scientific evidence to support it, but it is entirely possible.

A stroke is a result of blocking an artery in the brain. It causes part of the brain to die from a lack of oxygen. A stroke can be mild, moderate, or severe.

Like us, fish are susceptible to strokes due to bad conditions that put them at risk. Those conditions include high blood pressure, heart disease, and diabetes. 

A blockage in the arteries generally causes strokes in humans, but those in fish are genetically caused by a bacterial infection that results in swelling and inflammation of the brain.

Possible Stroke Symptoms in a Fish

Fish can have a stroke, but it is very rare

If your fish are struggling with a stroke, they may experience one or more of the following symptoms:

  • Challenging to swim in a straight line.
  • Breathe faster or swim more often without resting.
  • Their gills are open and flapping up and down.
  • The bottom half of the body begins to drift to one side.
  • Their eyes start blankly and are wide open.
  • They exhibit what looks like seizures or slow writhing movements.
  • Your fish show signs of weakness since they lose strength in their muscles
  • Your fish are not “swimming” anymore. Instead, drift aimlessly in one direction.

Here are some more signs that can indicate stroke or other serious issues:

  • Sagging.
  • Swirling.
  • Lethargy.
  • Convulsions.
  • Not eating.
  • Listlessness.
  • Loss of appetite.
  • Jerky movements.
  • Eating voraciously.
  • Losing their balance.
  • Floating upside down.
  • Loss of coordination.

It may not be easy to spot these symptoms, especially if you cannot notice subtle changes in your fish’s behavior.

Diseases With Stroke-Like Symptoms in Fish

Here are a few diseases that often confuse many fish keepers with a stroke. Let’s go through these diseases:

Swim Bladder Disorder 

All fish feature a swim bladder, helping them in many aspects of their physical swimming abilities. Swim Bladder Disorder involves a condition where the swim bladder of your fish doesn’t function normally.

That malfunction in a fish’s swim bladder can result from physical abnormalities in the bladder, diseases, or mechanical/environmental factors because of things going wrong with your tanks.

This disease may have many of the symptoms mentioned above, especially those involving the fish’s buoyancy. This disease shares many of the same signs as a stroke, so it is often misdiagnosed to be a stroke by many fish owners.

Brain Aneurysm

Fish have brains, and some may be more developed than others. That means, like other organs, there can be issues with it that lead to various symptoms and problems for your fish, which could cause death.

Brain aneurysms are rare with fish, but they are not impossible, especially in large fish species. A brain aneurysm refers to a blood vessel in the brain developing a colt, causing the blood to return to the blood vessel.

Then this leads the blood vessel in the brain to balloon or bulge. This bubble is an aneurysm that could leak or rupture at any time. Brain aneurysms will not lead to severe symptoms before rupturing, making them a time bomb.

Brain Tumour 

Fish have brain and body cells that can die and regenerate, like the cells in our bodies. That means your fish can have brain tumors, which are a collection or mass of abnormal cells inside their brains.

The skull of the fish is pretty rigid. Any abnormal growth inside this restricted, rigid space will most likely lead to problems for your fish. These tumors may be cancerous or noncancerous, depending on the makeup of the cells.

When those tumors begin to grow, they may increase the pressure in the skull of your fish. Then that pressure can cause several issues, such as brain damage or issues with motor functions, and it can cause a stroke.


How to Prevent Stroke in Fish?

How to Prevent Stroke in Fish?

  • Maintain clean water for your fish.
  • Make sure your aquarium is not overcrowded.
  • Feed your fish the right food.

Can Fish Have Aneurysms?

The short answer is yes. Aneurysms can be occurring with fish.

What Causes Fish to Swim Erratically?

It could be a form of play for your fish. If this behavior persists, it can be because of poor water quality.

Causes of poor water quality can be ammonia build-up, improper pH levels, high amounts of nitrites or nitrates, temperature changes, and more.

Can Fishes Feel Pain?

Fish can feel pain. It is likely different from what we feel, but it is a type of pain.


Can fish have strokes? The answer is yes, fish can have strokes, but this is a highly unlikely occurrence. Also, no conclusive medical evidence to prove that.

There are many signs that let you know that your fish is struggling with a stroke. 

But there are a few diseases that can cause your fish to have stroke-like symptoms; just remember that.

Thank you for taking the time to read the post!