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can tropical fish have seizures

Can Tropical Fish have Seizures?

Owning tropical fish is an enriching experience, and part of taking care of them is watching out for unnatural movements. Sudden movements in some fish types may be interpreted as a seizure, but any experienced aquarist will advise you against making assumptions because each fish type is different. So, can tropical fish have seizures? 

Tropical fish can have seizures, but that happens rarely. If you think your tropical fish is having a seizure, it’s likely a symptom of a different issue such as an infection, ammonia toxicity, a nerve or muscle disorder, shock, or ich. Tropical fish can get epilepsy, but this is also uncommon. 

This article will explain if tropical fish can have seizures and what would cause them. I’ll also clarify whether or not fish can get epilepsy. 

Can Tropical Fish Have Seizures?

If you own tropical fish, you probably already know that bacterial infections are common and can cause white spots and streaks on their bodies. But what about other conditions, such as seizures? Can tropical fish have seizures? 

Tropical fish can have seizures, but it’s uncommon. In most cases, seizure-like symptoms in tropical fish are a sign of other common conditions such as ich, shock, stress, muscle disorders, brain infections, etc.

According to the MSD Veterinary Manual, all fish are susceptible to neurological disorders. Fish have central, peripheral, and autonomic nervous systems. Abnormal electrical activity in the brain, an infection, and other conditions can affect nerve functioning. 

A study published on the National Library of Medicine’s website revealed that fish can have seizures, and the causes can be varied. 

Before assuming that your fish has had a seizure, you should rule out some other common conditions that can present similarly: 

  • The shimmies. When tropical fish “shimmy” (unnaturally moving the body, fins, and head), it’s a sign that they’re losing control of their muscles and nerves. This can be due to stress or living in an aquarium where the water is too cold or acidic. 
  • Infection. If your tropical fish has an infection that has affected its brain, its movements could look unnatural or jerky, and you might mistakenly believe it has had a seizure. 
  • New tank syndrome. Stocking your aquarium with fish before the biological filter works correctly and managing the bacteria levels can cause new tank syndrome. This can accumulate ammonia and cause your tropical fish to suffer from ammonia toxicity, a neurological condition.  
  • Old tank syndrome. Not replacing your aquarium water regularly can cause old tank syndrome. The water’s pH level can become too alkaline and kill the bacteria in the biofilter, resulting in high ammonia levels and seizure-like movements. 
  • Muscle disorders. Parasites in your tropical fish’s tank can cause muscle disorders. Pleistophora hyphessobryconis is a common aquarium parasite affecting a fish’s muscles. It can cause your fish to move unnaturally. 
  • Ich. Ich causes fish to develop white spots on their gills or skin and is caused by a parasitic infection. Scientists believe that it makes fish feel itchy, the reason they erratically rub against items in their aquarium and perform jerky movements. 
  • Shock. It’s a mistake to believe that fish don’t have well-developed brains because they can quickly experience shock in an environment that is too noisy, too bright, or too cold. 

If you’re not a trained veterinary professional, it can be challenging to rule out these conditions yourself, making it imperative to seek veterinary care from someone specialising in fish. 

What Causes a Fish To Have a Seizure?

In the previous section, I explained that although it’s rare for tropical fish to have seizures, it’s still possible. What causes a fish to have a seizure? 

An infection, epilepsy, injury, or a lack of oxygen can cause a fish to have a seizure. Unfortunately, it’s challenging to tell if your fish is having a seizure or is experiencing muscle or nerve problems, as the symptoms are similar. 

I’ll discuss the causes of seizures in fish in more detail below: 


It’s common for fish to get bacterial, parasitic, or viral infections, but they usually recover quickly and don’t require treatment. However, if the infection is severe and spreads rapidly, it can affect the fish’s central nervous system and compromise electrical activity in the brain. 

When this happens, fish can have a seizure. 


Epilepsy is rare, but some fish are born with a predisposition to it. Thankfully, the condition is extremely rare in fish, and if you have had your fish for a few months and it has never shown signs of seizures, he likely doesn’t have epilepsy. 

Vets don’t typically give anti-epilepsy medication to fish, so there’s sadly not much you can do if your fish has epilepsy. 


Fish love exploring their aquariums, moving in and out of rocky structures, and other obstacles. Unfortunately, they can sometimes injure themselves on items in the aquarium. If it’s a head injury, it can affect the brain’s functioning. 

Brain injuries can sometimes cause seizures in fish, and you can tell if your fish has been injured if it’s presenting with the following signs: 

  • Damaged fins
  • Bloated face
  • Injured eyes
  • Broken skin around the head

Lack of Oxygen.

If you don’t monitor and change the water in your fish’s aquarium regularly, it can become oxygen deficient. 

Oxygen-deficient water can cause hypoxia, a chronic lack of oxygen. If your fish’s brain doesn’t receive enough oxygen, it can start functioning erratically, sometimes resulting in seizures. 

Can Fish Get Epilepsy?

As I’ve explained in the previous section, fish don’t need to have epilepsy to have seizures. So, can fish get epilepsy? 

Fish can get epilepsy, and the condition is usually inherited. Thankfully, epilepsy in fish is much more uncommon than in mammals. If your young fish has never had seizures, there’s no way to tell if it has epilepsy unless it undergoes testing in a lab.


If you see your tropical fish making sudden, jerking movements, it may be having a seizure. This is, however, rare, and seizure-like movements in tropical fish are usually caused by: 

  • The shimmies
  • An infection
  • New or old tank syndrome
  • Muscle disorders
  • Ich
  • Shock

If you’re worried about your tropical fish making unnatural movements, it’s best to consult a vet who specialises in fish. 

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