Betta fish abdominal swelling can be caused by multiple factors. Here are common scenarios and corresponding treatment methods:
1. Ascites (Severe Disease)
Symptoms
- Abdomen swells abnormally to both sides (non-uniform bulge), accompanied by loss of appetite, lethargy, or staying at the tank bottom.
- Complications like pinecone scales (scales standing upright) or bulging eyes may occur in late stages.
Causes
- Internal organ failure due to poor water quality, low-quality feed, or parasitic infections.
Treatment Recommendations
- Antibiotic Therapy: Bath with kanamycin, tetracycline, or mix with food.
- Early Intervention: Combine gentamicin and oxytetracycline, paired with a 3-day fasting period.
- Supportive Measures: Raise water temperature to 30°C and maintain stable water quality.
2. Egg Binding (Normal Physiological Phenomenon in Female Bettas)
Characteristics
- Rounded, uniform abdominal swelling with no abnormal behavior.
Management
- No intervention needed; keep the environment quiet.
3. Constipation or Indigestion
Diagnosis
- Abdomen bulges temporarily after feeding and relieves after defecation.
Treatment
- Fast for 1–2 days, then control feeding portions.
4. Tumors or Other Pathologies
Characteristics
- Asymmetrical abdominal swelling, possibly with localized hard lumps.
Management
- No effective treatment currently; isolate and observe the fish.
Prevention Measures
- Water Quality Management: Regular water changes; avoid leftover feed accumulation.
- Feed Selection: Prioritize safe, frozen-killed foods like bloodworms and brine shrimp.
- Environment Optimization: Avoid sharp aquatic plants or substrate that traps debris.
If symptoms persist or worsen, isolate the affected fish immediately and consult a professional aquarium veterinarian.