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The Most Common Pleco Diseases and Illnesses

The Most Common Pleco Diseases and Illnesses

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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.

Taking care of plecos in your fish tank should be a great experience. These fish are fun to observe, and they’re going to be great additions to community fish tanks.

Most plecos aren’t too difficult to take care of. That doesn’t mean that things can’t go wrong, though.

Plecos are susceptible to certain diseases just like other fish. There are a number of pleco diseases that you should be aware of.

Read on to learn about many different types of fish diseases that can impact plecos. This will help you to know what to look out for so that you can protect your fish.

Fin Rot/Dropsy

Patriot Betta With Fin Rot
Patriot Betta With Fin Rot

Fin rot and dropsy are being put in the same section because they’re both problematic bacterial diseases. They’re different conditions, but they both have similar causes.

Typically, fish are more likely to experience fin rot or dropsy when the water conditions in the tank aren’t good. Dirty water can cause plecos to become stressed, and this will make them develop compromised immune systems.

A fish with immune system issues will be more prone to becoming infected by bacteria. You might notice that your fish will have a bloated appearance if it has dropsy.

Fish with dropsy usually start looking bloated and they often lose coloration. Fish might start looking lethargic as well.

Lethargy and a lack of appetite are common signs of fin rot issues. If the condition worsens, then the fins might start to appear ragged.

The infection can literally eat away at the fins of the plecos. It’s a condition that you will want to treat as soon as possible.

Treating bacterial diseases such as these will involve giving the fish antibiotics that are formulated for gram-negative bacteria. You’ll also need to fix issues with the fish tank that might have caused the fish to get sick in the first place.


Snakeskin Barb With Ich or White Spot Disease
Snakeskin Barb With Ich or White Spot Disease

Ich is one of the most common diseases that plecos have to deal with. This is a parasitic disease that causes white spots to appear all over the body of the fish.

When fish have ich, they will start to feel very uncomfortable. You might notice the fish trying to rub up against objects in the tank.

They do this to try to find relief. Fish will also lose their appetite when they have ich and they might become lethargic as well.

Typically, plecos will get ich if they are kept in dirty water. Poor water quality makes it more likely that the fish will become infected.

It’s possible to kill the ich parasites off by giving plecos medication. If all goes well, your fish should get better.

You’ll need to fix issues with the tank as well, though. Ensure that the water is clean and that the water parameters are in the right range.

Cloudy Eye

Cloudy eye is another common problem for plecos. This is a disease that is known to cause the eye of the fish to become covered with slime.

The slime will be either gray or white. The clouded vision of the fish makes it harder for it to get around.

Often, you’ll see fish awkwardly swimming around in the tank when they have cloudy eye. This condition is usually related to poor water quality.

Improving the water quality and caring for the fish carefully should help to clear things up. In the future, it’ll be best to be careful to keep the water quality high.

Pop Eye

Goldfish with Popeye
Goldfish with Popeye

Pop eye is a disease that causes the eyes of the fish to protrude. In some cases, fish might wind up losing an eye due to this serious problem.

When you don’t treat the fish properly, it’s possible that the fish will either lose vision in the eye or it’ll lose the eye entirely. Sometimes fish will experience this issue in conjunction with cloudy eye.

It’s also notable that this disease can impact either one eye or both eyes. Symptoms include loss of appetite, swelling in the body, clamped fins, and lethargy.

Pop eye can be caused by either an injury to the eye or some type of infection. Poor water conditions are known to contribute to the disease.

Treating the condition involves solving problems that might have caused the fish to get pop eye in the first place. If poor water conditions are to blame, then you’ll want to fix those problems first.

It might be necessary to treat the fish using aquarium salt since that could relieve the swelling. Move the fish to a quarantine tank and it should get better over time.

Fungal Infections

Cotton Mouth Fungus on Black and Yellow Angelfish
Cotton Mouth Fungus on Black and Yellow Angelfish

Fungal infections are somewhat common concerns for plecos. A pleco might develop a fungal growth on its body that will look gray or white.

Often, this fungal growth is said to look like a cotton ball. This disease is caused by a type of water mold known as an oomycete.

This is usually a secondary infection that occurs due to some type of skin problem. If a fish has been scraped by ramming into an object in the tank, then this might give a breeding ground for the oomycetes.

Dirty water makes it easier for the fungus to thrive in a fish tank. Thus, if you’re not doing regular water changes, you might be making it easier for your fish to get infected.

Fungal infections require medical treatments. You’ll need to give the fish antifungal medications and improve the water quality in the tank.

Hole in the Head Disease

Hole in the Head Disease on Purple Tang
Hole in the Head Disease on Purple Tang

Hole in the head disease is a common disease for many types of freshwater fish. It’s also referred to as Head and Lateral Line Erosion (HLLE).

The scary thing about this condition is that the cause is not yet understood. Many say that the parasite known as Hexamita is the primary cause of hole in the head disease.

This parasite can infect many places such as the spleen, intestinal tract, gallbladder, and kidneys. As the disease gets worse, lesions will begin appearing on the head of the fish.

These lesions will get worse over time, and they often lead to secondary infection. The secondary infections have the potential to kill the pleco fish.

Treating this condition usually involves trying to get rid of the parasites. Antibiotic treatments should help with infections, and you’ll also want to closely monitor the water quality.

Ensure that the fish eats a healthy diet and it should have a chance of getting better. If the fish eats well and the water stays in good condition, the health of the fish should improve over time.

Final Thoughts

You’ve learned about the common diseases that plecos have to deal with. Just because these are common pleco diseases doesn’t mean that your plecos need to get sick.

It’s possible to protect your plecos by doing a good job monitoring the conditions of the tank. Many of these diseases are more likely to occur if the fish are kept in dirty water.

Poor water quality can have a very negative impact on all fish. You need to regularly clean the fish tank, and doing weekly water changes will also be important.

Do your best to test the pH balance of the water regularly to keep the water parameters in check. Adjust things as necessary and continue to care for the plecos.

Feed the plecos the food that they need to stay healthy. Ensure that they have more than enough space to be able to thrive in your tank.

Taking all of these steps should make it easy to keep the plecos safe. It’ll be far less likely that you’ll need to deal with the diseases mentioned above.

If the fish ever do get sick, then treat them with the appropriate medications and methods as soon as you can. Plecos have an average life span between 10 and 15 years when given optimal care, and you should be able to keep diseases from claiming them sooner by taking the right precautions.

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