Home Fish Facts Can Fish Have Strokes? (Helpful Examples)

Can Fish Have Strokes? (Helpful Examples)

by gvald

This is a question we can ask ourselves when we see how some fish react to certain situations. Some even find themselves swimming backwards, one could almost think that they have lost consciousness.


Can fish have strokes?

It is very unlikely that your fish will have a stroke, but the phenomenon that may lead you to think that your fish is having a stroke is surely a disease or a parasite that has taken hold of your fish, here are some of the most known parasites and diseases on fish according to their symptoms.


Diseases that make the fish looks like he’s having a stroke

If you are in doubt about the health of any of your fish and you see any of the signs that it is sick, transfer it to a quarantine aquarium that is always available.



A shimmy is when the fish appears to be swimming in place. Its fins move, but it does not move forward. The cause is often a low water temperature or a sudden drop in temperature.



If your fish bumps into the decor, windows or rubs against the floor, it is called flashing. He is simply trying to scratch himself. If this behavior persists, it is possible that your fish has external parasites.


Eye swelling

If one or both eyes are swollen, it could be a viral, bacterial or fungal condition.


Increased breathing

You may notice that your fish is breathing faster than usual and is flailing around, sucking air from the surface. There is an oxygen deficiency in the water.


Can fish diseases be transmitted to humans?

Don’t panic, 99% of the diseases and parasites that fish contract are absolutely not transmissible to humans, so there is almost no chance that your fish will give you its disease, simply because you are not composed in the same way as they are.


How to recognize parasites and treat your fish

Anchor worm (Lerneosis), lice


Presence of parasites on the skin, gills and mouth. Erosion and ulceration. Red spots on the skin that can be up to 5 mm



Identifiable with a magnifying glass, prolonged treatment with salt (freshwater species). Treatment with hydrogen peroxide, formalin and ivermectin which are remedies against lice.




Scratching of fish on tank walls, release of mucus from gills, rapid movement of gills, and damage to fins and gills. Pallor, rapid breathing and agitated fins.



10 to 30 minute treatment in a 10 mg per liter potassium permanganate bath in a separate tank (freshwater parasite only). Salt bath (freshwater parasite only). Formalin or copper bath.




Presence of parasites on the skin, creation of small red or white lesions. Heavy infestations lead to anemia.



Avoid introduction of wild plants and snails, bath in saline solution, use of organophosphates.




Progressive weight loss, lethargy, empty stomach and accumulation of parasites around the anus. Colonization of viscera with 0.6-7.0 mm worms in the intestine.



Medicated feedings with oral fenbendazole, oral levamisole.

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