Angelfish Diseases

Generally, angelfish have thin bodies which are flattened laterally. They show a wide variety of colors. This specialty makes them popular and well-liked aquarium species. It’s stated that angelfish have been named due to the fins appearing like angel wings. So in this article, we will discuss angelfish diseases and how to cure them easily.

Angelfish is prone to many diseases. We should take proper care of them to keep them free and safe from disease.

The factors on which fish health depends are first-class water, which is the quality of water free from contamination; irregular care; inappropriate filtration, which includes an imbalance of osmolarity; and improper feeding.

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Angelfish Diseases and Treatment

Following are the angelfish diseases they are prone to:

Angelfish Fin Rot

How do you identify angelfish fin rot

Fin rot is a very common disease in angelfish. This is caused by either bacteria or fungus. The fins and tails become short. The damaged fins become red and inflamed. The heater is a must for angelfish because it helps prevent from finrot cause.

Signs and Symptoms

Angelfish Fin Rot Signs, Symptoms and Remedies

It includes discoloration of the fin at the edges, reddened, inflamed skin, anorexia (loss of appetite), and the appearance of red, brown, or white spots over the body, fins, and tail.

Remedies and medications


Separate the affected fish and start with the following medications.


Treatment of antibacterial or antifungal. The most common treatment such as phenoxyethanol is used.

Aquarium salt 

Keep changing the tank’s water. Add aquarium salt that is suitable for aquariums. Avoid crowding in the tank.

Angelfish Dropsy

how to know angelfish dropsy disease

The word “dropsy” is an old medical term. These days, dropsy is considered an edema. Edema is the swelling of soft tissues. Commonly, this refers to the swelling of the stomach. Most often, this refers to swelling of the stomach. This can occur due to the collection of fluid in the body. In human medicines, the term edema is in use, meanwhile, the term dropsy is used for aquarium fish. Dropsy is the medical condition of fish having swollen bellies. It includes bloating.

Signs and Symptoms

Angelfish dropsy Signs, Symptoms and Remedies

It includes the signs like swollen belly, pale excreta, protrusion of eyes, anorexia (loss of appetite), discoloration of the fish, etc.

Remedies and medications


Firstly, separate the impacted fish and start the following treatment.

Aquarium salt

After putting it in the special treatment tank, add one teaspoon Epsom of salt for each gallon of water.


Give healthy food. Treat the fish with antibiotics. Keep testing the water quality frequently. Maintain the osmolarity of the water.

Angelfish Hexamita

How do you identify Angelfish Hexamita

Hexamita is a parasite that enters the fish. It is a flagellated protozoan. This parasite is found in the intestinal tract of fish species. Hexamita production is enhanced by populated tanks and poor-quality water. It decreases the immune system of fish, and the lesion can be seen on the fish’s head.

Signs and Symptoms

Angelfish Hexamita Signs, Symptoms and Remedies

It includes the signs such as white excreta, weight loss, denial of food, loss of appetite, weakness, protrusion of eyes, distended abdomen, etc.

Remedies and medications


The fish suffering from an illness should be quarantined into a different tank.

Aquarium salt 

An aquarium salt bath should be provided. Add 2 teaspoons of aquarium salt to every gallon of water.


Metronidazole is the most recommended treatment for hexamita. Medications should be given through food. In the case of anorexia, you can treat the aquarium water. Provide a healthy fish diet.

Angelfish Anchor worms

How do you identify Angelfish Anchor worms

Signs and Symptoms

Angelfish Anchor worms Signs, Symptoms and Remedies

There are signs like irritation of the skin, red lesions on the skin, inflamed skin, weakness, and anchor worms that appear like thread-like structures on the fish.

Remedies and medications

They are not easy to treat. Anti-parasite medications should be recommended. Following are the guidelines for administering medications.


Separate the affected fish and treat it in a different tank. Keep checking the water quality.

Removing worms

You can use forceps for grasping the worm. Take care that your fish is not out of the water for more than one minute. Repeat the procedure in 30 minutes if it remains impending in the previous trial.

Aquarium salt

Provide a salt bath to the affected fish. Add 2 teaspoons of aquarium salt to every gallon of water.

Angelfish velvet disease

How do you identify Angelfish velvet disease

Piscinoodinium is the name of the parasite that causes velvet disease. Once the parasite enters the aquarium, it looks for a live host to feast on. The fish die quickly because the fish that suffer from this illness are typically consumed from the inside. Velvet disease is the most common angelfish disease. The affected fish should be treated quickly as this disease is highly contagious.

Signs and Symptoms of velvet disease in angelfish

Angelfish velvet disease Signs, Symptoms and Remedies

Gold coating 

The gold coating is the most superficial sign that covers the skin. It also includes protrusion of the eyes.

Peeling skin 

The skin begins to peel from the angel fish’s body when velvet disease gets to be progressed. Ulcers can be observed alongside. Signs like loss of appetite and rapid breathing are also seen in velvet disease.

Remedies and medications


Quarantine the affected fish and keep it in a special tank.

Aquarium salt

Treat the disease with fish salt. Add 2 teaspoons of aquarium salt for every gallon of water.


Proper drugs should be given to the fish. The most commonly used medication for velvet disease is copper sulfate. Copper sulfate helps in killing bacterial, fungal, and parasitic infections. Don’t give copper if it contains too low a pH. You can also provide vitamins by feeding your fish with vitamin A and vitamin E. Check the ideal quality of water that helps to maintain the health of angelfish.

Angelfish Cotton Wool Disease

The cotton wool disease is a bacterial disease that is caused by Flavobacterium columnare. This disease infects the pores, skin, and gills of this fish. A fish with a poor immune system is prone to get affected by this pathogen. The cotton wool disease is also known by various names, such as cotton mouth disease, saddleback disease, black patch necrosis, and columnaris disease. If left untreated, this disease is extremely contagious and probably deadly.

Signs and Symptoms

Skin patches

The most common sign that is noticeable is the Cotton wool disease.

Pale Gills

While inspecting, the tissues of the gills then appear pale.

Loss of Appetite

The affected fish have difficulty feeding.

Difficulty swimming

The affected fish loses its balance and finds difficulty swimming.

Remedies and medications


Separate the suffering fish and keep it in a hospital tank to avoid the infection spreading. 

Salt bath

Use aquarium salt and provide a salt bath to the affected fish. Add 2 teaspoons of aquarium salt for every gallon of water.


Give your pet antibiotics that are prescribed by a veterinary doctor. Antibiotics like terramycin and acriflavine may work. 

Angelfish Pop-eye Disease

How do you identify Angelfish Popeye disease

Pop-eye fish is a condition of bulging or protrusion of one or both eyes. Pop-eye is caused by the accumulation of fluid in the eye. It is also caused by pathogens or poor water quality. If left untreated, pop-eye can cause blindness or maybe even death. 

Signs and Symptoms

Angelfish Pop-eye Disease Signs, Symptoms and Remedies

Protrusion of eyes

Protrusion of one or both eyeballs It also includes the appearance of cloudy eyes.

Discoloration or blood in the eyeball

The infection causes blood in the eyeball.


Fish’s immune system becomes weak, which results in lethargic conditions.


Along with the disease, the most common cause is improper water temperature, which makes your pet inactive.

The other symptoms include loss of appetite, rupture of the eyeball, swollen body, etc.

Remedies and Medications


Isolate the sick fish and keep it in a special tank for further treatment. 

Salt bath

Provide a salt bath to your pet with proper aquarium salt; add 2 teaspoons of aquarium salt with every gallon of water.

Water Quality

Keep checking the water quality and maintain the osmolarity of the tank. Keep an ideal temperature for the fish.


Antibiotics are prescribed by a veterinarian in this condition. Antibiotics are prescribed according to the type of bacteria, whether they are gram-positive or gram-negative. For instance, erythromycin is given in the case of gram-positive bacteria.

Angelfish Virus infection 

Angelfish virus infection is a highly contagious disease. This disease is mainly caused by herpesviruses[1] (Pterophyllum spp). Fish with a low immune system are prone to this infection, and they will come down with signs and symptoms within 2–3 days of exposure, generally quicker. 

Signs and Symptoms

Clamped fins

The virus infection in the fish makes their fins so close to the body that they are not able to open their fins properly. It is also caused by improper water temperatures and poor water quality.

Weight loss

Loss of appetite will lead to weight loss in your pet. 


This is a lethargic condition that is followed by a weak immune system.

Remedies and Medications


Remove the affected fish and isolate it in a special tank. Follow the treatment guidelines for the suffering fish once it has shifted. 

Water Quality

Keep checking the water quality. Maintain proper filtration in the tank.

Salt bath

Add aquarium salt according to the proper quantity of water and provide a salt bath to your pet. 


Unfortunately, this disease is not easily curable. If an angelfish survives the virus, it will be the carrier of the virus for up to the next 6 months. Mainly, nalidixic acid is the medication recommended by veterinarians.

Angelfish mouth fungus disease 

Angelfish mouth fungus[2] is caused by a bacterium known as Flavobacterium columnare, which is a gram-negative bacterium. This bacterium is found in aquariums. The bacteria doesn’t affect fish under normal conditions.

But, these bacteria take advantage when they arise and enter the body of your angelfish through a cut, lesion, or any injury. 

Signs and Symptoms


Tachypnea is an abnormal condition characterized by rapid breathing.

Fin rot 

Fin rot or ragged fins are caused by bacterial infection. Fin rot is the decay of fins.

Excessive production of mucus

Mucus is produced in excess in the regions such as the gills and head.

Cotton-like threads 

These are observed at the face, mouth, and gills.

Remedies and Medications


Isolation of sick fish is very important for furthering the cure and preventing other fish from getting affected.

Salt bath

Add aquarium salt or sodium chloride to the tank with the measurement of 6 teaspoons of solute per gallon of water. This method helps in preventing disease.


Antibacterials such as phenoxyethanol or nifurpirinol are recommended in this case. 

Angelfish Swollen Bellies  

Swollen bellies are a very common problem among angelfish, and there are both physiological and pathological reasons behind them.

Physiologically, swollen bellies are due to pregnancy and eggs. Meanwhile, pathologically, it includes diseases and medical conditions like tumors, constipation, and dropsy. In tumors, the fish can get tumors in their stomach and its relative organs. Constipation occurs due to the consumption of too much food. Dropsy is a disease that refers to the swelling of the abdomen that is caused by the accumulation of fluid.

Signs and Symptoms 

Swollen Belly

This is the most common and first noticeable sign that you can see in your pet.

Loss of appetite 

The sick fish have difficulty feeding and an upset stomach.

Protrusion of eyes

Bulging eyes or an increase in the size of one or both eyeballs

Remedies and Medications


The affected fish are removed and shifted into a hospital tank for further treatment. It includes special care with proper treatment.

Salt bath

Provide a salt bath for your pet by adding aquarium salt to the tank. This helps in preventing disease.


The veterinary doctor will determine the cause of swollen bellies in angelfish, whether it is physiological or pathological, and the medicines should be prescribed accordingly

Angelfish Gill Flukes 

The gill flukes are caused by parasites. The parasite mostly affects the fish gills. It becomes hard for the fish to suffer from this disease. It may prove fatal if left untreated.

Signs and Symptoms

Redness near gills

The redness occurs near gills, the flukes are responsible for this because they consume your fish’s blood.

Breathing issues

Fish suffer from heavy breathing.

Loss of appetite

The affected fish have difficulty feeding.

Remedies and Medications


Isolate the sick fish, and provide the proper treatment

Salt bath

Provide a salt bath with aquarium salt to your affected pet.

Water quality

Keep checking the water quality and maintain the osmolarity of the tank.


Antiworm medication Praquizantel is prescribed by a veterinary doctor in this case

Fact about angelfish

Dena Edwards, President of The Angelfish Society[3] and an angelfish breeder for 10 years, said she often hears complaints from new angelfish owners about their fish eating other fish.

“In the wild, angels eat neon tetras, so it should especially be no surprise that this breed will eat neons in an aquarium,”

she said.


As angelfish are more prone to diseases, this article concludes that you should be more preventive than curative. To keep your pet wholesome and unfastened from disease, constantly keep checking their water quality, filtration, and osmolarity, and feed them on time. Provide your pet with a vet visit on time. Clean out the tank every week. Keep checking the swimming and appetite status. If you follow the stated guidelines, your pet will be happy and healthy. 


What is the angelfish virus?

There is no such thing as the “angelfish virus.” Angelfish can be susceptible to a variety of viral infections, as well as bacterial and fungal infections. However, each specific infection has its name and symptoms.

What is velvet disease on angelfish?

Velvet disease is a common fish disease caused by the parasite Oodinium pillularis. It appears as a fine dusting of yellow or brownish-gold “velvet” over the skin of infected fish. Other symptoms include labored breathing, loss of appetite, and lethargy. Treatment typically involves removing infected fish from the main tank and treating them with a medication specifically designed to combat velvet disease.

What is the white stuff on my angelfish?

The white stuff on your angelfish could be a few different things, depending on the location and appearance. A mucus-like coating around the fish’s mouth or gills could be a sign of a bacterial or fungal infection. If it’s small white spots scattered across the body, it may indicate ich, another common parasitic infection. Finally, if the white substance appears more like a growth or lump on the fish’s body, it could be an external tumor.

What is black spot disease angelfish?

Black spot disease is a parasitic infection that affects many species of fish, including angelfish. It’s caused by flatworms of the genus Neascus, which attach themselves to the skin and scales of the fish. Infected fish develop dark, circular spots on their bodies (hence the name “black spot”), and may also show signs of irritation and inflammation. Treatment often involves medicated baths or dips to kill the parasites, as well as improving overall tank conditions to prevent future outbreaks.

How do you save a sick angelfish?

Saving a sick angelfish depends on identifying the specific illness and providing appropriate treatment. The first step is to observe the fish for any symptoms such as lethargy, loss of appetite, visible signs like discoloration or growth, and abnormal behavior. Once the illness is identified, steps can be taken to isolate the sick fish and treat it with medication, improved water quality, or other measures as necessary. It’s important to act quickly to prevent the spread of illness to other fish in the tank.

What is velvet disease on angelfish?

Velvet disease is a common parasitic infection that affects angelfish and other aquarium fish. It is caused by the parasite Oodinium pillularis and appears as a fine dusting of yellow or brownish-gold “velvet” over the skin of infected fish. Symptoms include labored breathing, loss of appetite, and lethargy. Treatment involves isolating infected fish and treating them with medication specifically designed to combat velvet disease. Improving overall tank conditions, such as water quality, can also help prevent future outbreaks.

What does a stressed angelfish look like?

A stressed angelfish may exhibit various symptoms, including gasping at the surface or rapid breathing, hiding, darting around the tank, loss of appetite, and clamped or folded fins. They may also appear discolored, with faded or washed-out colors. Stress can be caused by poor water quality, overcrowding, sudden changes in temperature, or other factors. Identifying and addressing the underlying cause of stress is essential to improving the fish’s health and preventing further harm.

What is the average lifespan of an angelfish?

The average lifespan of an angelfish is typically around 10 years, although they can live longer if provided with optimal care. Factors that affect the lifespan of angelfish include water quality, nutrition, and tank size. Providing a healthy diet, regular maintenance of the aquarium, and appropriate tank mates can help maximize the lifespan of these beautiful fish.

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