Dropsy In Angelfish: Causes, Treatment, Prevention

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Angelfish are known for their hardiness in home aquariums, making them a popular choice for many fish enthusiasts. Yet, they can still fall ill.

In this discussion, I’ll delve into Dropsy in Angelfish.

What exactly is this ailment? How can you identify and address it? What can you expect in terms of recovery? Let’s dive right in.

What Exactly Is Dropsy in Angelfish?

Dropsy in angelfish is a condition characterized by fluid accumulation in the body tissues or cavity, leading to swelling and bloating.

It’s typically a symptom of underlying issues like bacterial infections, poor water quality, or organ failure.

The disease manifests through symptoms like a swollen belly, scales sticking out, and lethargy, making early detection and treatment crucial for the fish’s survival.

Also Read: Angelfish Diseases

What Are the Symptoms of Dropsy Disease in Angelfish?

Dropsy disease in angelfish is primarily recognized by its distinct swelling and bloating of the fish’s body, often resembling a pinecone due to the protruding scales.

These symptoms are usually accompanied by other signs of distress and illness that indicate a serious internal problem.

  • Swollen Belly: The fish’s abdomen appears unusually swollen or enlarged, which is a clear sign of fluid accumulation inside the body.
  • Protruding Scales: The scales of the affected angelfish start to stick out, giving the fish a pinecone-like appearance, which is quite distinctive.
  • Lethargy: Affected fish often exhibit reduced activity levels, swimming less and showing a general lack of energy or enthusiasm.
  • Loss of Appetite: Dropsy can lead to a noticeable decrease in the fish’s appetite, where it shows little interest in food.
  • Bulging Eyes: In some cases, dropsy can cause the eyes of the angelfish to bulge out, a condition known as exophthalmia.

Causes of Dropsy Disease in Angelfish

These are the leading causes of Dropsy in Angelfish:

1. Bacterial Infections

Bacterial infections in angelfish are a common cause of dropsy, usually arising from harmful bacteria present in their aquatic environment.

These pathogens attack the fish’s internal organs, leading to fluid accumulation and the typical symptoms of dropsy.

  • Symptom Identification: Rapid breathing, red streaks or ulcers on the body, and a swollen abdomen are indicative of bacterial infections.
  • Common Bacteria: Aeromonas and Pseudomonas species are frequently involved in these infections, thriving in poorly maintained tanks.
  • Pathogenic Mechanism: These bacteria can invade the fish’s body, causing systemic infection and organ damage that results in fluid accumulation.

2. Poor Water Quality

Poor water quality is a significant factor in the development of dropsy in angelfish, as it stresses their immune system and makes them more susceptible to diseases.

  • Symptom Identification: Cloudy water, foul odor, or fluctuating pH and ammonia levels are signs of poor water quality.
  • Impact on Health: Toxins like ammonia or nitrites in the water can directly damage the fish’s internal organs, leading to conditions like dropsy.
  • Water Quality Parameters: High levels of nitrates, low oxygen levels, and imbalanced pH are specific water quality issues that can lead to health problems in angelfish.

3. Parasitic Infestations

Parasites can cause dropsy in angelfish by infecting and damaging their internal organs.

  • Symptom Identification: Erratic swimming, rubbing against objects, and visible spots or worms on the body indicate parasitic infestations.
  • Types of Parasites: Flukes and worms are common parasites in aquarium fish, capable of causing significant internal damage.
  • Parasitic Damage: These parasites can harm the angelfish’s internal organs, particularly the kidneys, leading to fluid accumulation and swelling.

Also Read: Black Spots On Angelfish

4. Malnutrition

Malnutrition in angelfish can lead to dropsy by weakening their immune system and overall health, making them more susceptible to diseases that cause fluid accumulation.

  • Symptom Identification: Signs of malnutrition include weight loss, faded colors, and lethargy in the fish.
  • Dietary Needs: Angelfish require a balanced diet rich in nutrients; a deficiency can lead to weakened organ function and health.
  • Effect on Health: Chronic malnutrition can compromise the angelfish’s ability to regulate fluid and electrolyte balance, leading to dropsy.

5. Organ Failure

Organ failure, particularly of the kidneys or liver, is a critical cause of dropsy in angelfish, as these organs are essential in maintaining fluid balance.

  • Symptom Identification: Symptoms indicative of organ failure include severe bloating, loss of appetite, and abnormal swimming behavior.
  • Organ Function: The kidneys and liver are crucial for excreting waste and regulating body fluids; their failure disrupts these processes.
  • Resultant Condition: When these organs fail, they can no longer regulate fluid, leading to the characteristic fluid accumulation seen in dropsy.

Treatment Approaches for Dropsy in Angelfish

To assist your Angelfish in bouncing back from Dropsy, it’s crucial to tackle the underlying issue. Here’s what you should do:

1. Antibiotic Treatment for Bacterial Infections

Antibiotic treatment is essential for angelfish with dropsy caused by bacterial infections. Selecting the right antibiotic based on the type of bacteria is crucial for effective treatment.

  • Specific Antibiotics: Use antibiotics like Kanamycin or Tetracycline, effective against gram-negative bacteria; a typical course lasts 7-10 days.
  • Dosage Accuracy: Ensure precise dosing, usually around 5-10 mg per liter of water, depending on the specific medication and severity of infection.
  • Isolation of Fish: Move the affected fish to a separate tank to administer treatment and avoid spreading the infection to other fish.
  • Monitoring Water Quality: Regularly check water parameters, aiming for ammonia and nitrite levels at 0 ppm and nitrates below 20 ppm during treatment.

You could also try over-the-counter products like Seachem PolyGuard (link to Amazon). Make sure to follow the manufacturer’s instructions.

2. Improving Water Quality and Conditions

Ensuring optimal water conditions is a key step in both treating and preventing dropsy in angelfish.

Maintaining a stable and clean environment reduces stress and disease susceptibility.

  • Regular Water Changes: Perform 25-30% water changes weekly, or more frequently if necessary, to maintain water quality.
  • Control of Parameters: Keep the water temperature at 76-82°F and pH levels between 6.8 and 7.8 for ideal angelfish conditions.
  • Filtration System: Use a high-quality filtration system to remove physical and chemical contaminants, and check the filter regularly for maintenance. I found the Fluval C4 Power Filter (link to Amazon) to be extremely useful on this matter.
  • Testing Water Regularly: Use a water testing kit to monitor ammonia, nitrite, and nitrate levels, keeping them within safe ranges. My recommendation: API Freshwater Master Test Kit (link to Amazon).
My API Freshwater Master Test Kit

3. Antiparasitic Medications for Parasitic Infestations

Treating parasitic infestations in angelfish with appropriate antiparasitic medications is crucial. Identifying the specific type of parasite will guide the choice of medication.

  • Appropriate Medication: For parasites like flukes, medications such as Praziquantel are effective; the treatment duration varies based on infection severity.
  • Dosing Guidelines: Follow the recommended dosage, typically around 2.5 mg per liter, adjusting as needed based on the fish’s response.
  • Quarantine Infected Fish: Isolate affected fish in a separate tank to prevent the spread of parasites and for easier treatment.
  • Observation Post-Treatment: Monitor the fish for a few weeks post-treatment to ensure the complete eradication of parasites and recovery of health.

To fight parasitic infections, you can also use over-the-counter products like Hikari Prazipro (link to Amazon).

To effectively use Hikari Prazipro, add one teaspoon per 20 gallons of aquarium water, distributing it evenly or directly into the filter box, and treat for 5-7 days.

4. Nutritional Supplements and Balanced Diet

Providing a balanced diet and nutritional supplements is crucial in treating dropsy in angelfish, especially if malnutrition is a contributing factor.

A well-rounded diet strengthens their immune system and helps in recovery.

  • Varied Diet: Include a mix of high-quality flakes, pellets, frozen or live foods like brine shrimp or bloodworms to ensure a balanced diet.
  • Vitamin Supplements: Add vitamin supplements to their food; for instance, Vitamin C and E supplements can boost the immune system. My recommendation: Seachem Nourish (link to Amazon).
  • Feeding Frequency: Feed small amounts 2-3 times a day to avoid overfeeding and ensure proper nutrition without polluting the water.
  • Observation of Eating Habits: Closely monitor their eating habits; a return of appetite is a good sign of recovery.

Also Read: Angelfish Constipation

5. Supportive Care for Organ Failure

When dropsy is caused by organ failure, supportive care is critical as part of the treatment. 

This involves managing symptoms and providing a stress-free environment to aid in the healing process.

  • Optimal Tank Conditions: Maintain ideal water parameters; a stable temperature of 76-82°F and pH levels between 6.8 and 7.8 are essential.
  • Stress Reduction: Minimize stress by providing a quiet environment, adequate hiding spots, and avoiding overcrowding in the tank.
  • Water Cleanliness: Ensure the tank is clean with regular water changes and efficient filtration to prevent further stress on the fish’s organs.
  • Regular Monitoring: Keep a close watch on the fish for any changes in behavior or appearance, which can indicate the progression or improvement of the condition.

Prognosis for Angelfish with Dropsy Disease

The prognosis for angelfish with dropsy varies greatly, depending largely on the stage of the disease when treatment begins.

In many cases, dropsy can be fatal, but early detection and appropriate treatment can improve chances of recovery.

  • Early Detection: If dropsy is caught early and treated promptly, the survival rate can be as high as 50-60%.
  • Advanced Stage: For angelfish in advanced stages of dropsy, the prognosis is poor, with survival rates dropping to less than 10-20%.
  • Underlying Causes: Recovery chances are higher if the cause is treatable, like bacterial infections, but lower for irreversible conditions like organ failure.

Preventing Dropsy Disease in Angelfish

Prevention of dropsy in angelfish involves maintaining optimal aquarium conditions and monitoring the fish’s health.

Regular care and attention can significantly reduce the risk of this disease.

  • Maintain Water Quality: Keep the tank clean with weekly water changes of 25-30%, and ensure ammonia and nitrite levels are always at 0 ppm.
  • Balanced Diet: Feed a varied diet of high-quality flakes, pellets, and live or frozen foods to ensure proper nutrition and immune system health.
  • Regular Health Checks: Observe your angelfish daily for signs of stress or illness, such as changes in behavior or appearance.
  • Quarantine New Fish: Always quarantine new fish for at least 2-3 weeks before introducing them to your main tank to prevent the spread of diseases.


For quick readers, here’s a short summary:

  • Dropsy in angelfish is a serious condition marked by swelling due to fluid accumulation, often caused by bacterial infections, poor water quality, or organ failure, and requires early treatment.
  • Symptoms of Dropsy include a swollen belly, protruding scales, lethargy, loss of appetite, and bulging eyes, signaling the need for immediate attention to the fish’s health.
  • Effective treatment for Dropsy involves addressing the root cause, such as using antibiotics for bacterial infections, improving water quality, administering antiparasitic medications, and ensuring a balanced diet.
  • The prognosis for angelfish with Dropsy varies; early detection and treatment can lead to a 50-60% survival rate, but chances diminish significantly in advanced stages of the disease.
  • Preventing Dropsy in angelfish centers around maintaining high water quality, feeding a balanced diet, conducting regular health checks, and quarantining new fish to reduce disease risk.