Exophthalmia (Popeye Disease) is a common condition in betta fish, which can be caused by poor water quality, bacterial infections, parasites, or improper care. Below is a comprehensive analysis and solution guide:
I. Main Causes and Symptoms
1. Deteriorated Water Quality
Infrequent water changes and excessive ammonia/nitrite levels can cause edema (swelling) in the eye tissues.
Accompanying symptoms: Pale gills and redness/inflammation on the body surface.
2. Bacterial or Parasitic Infections
Bacteria (e.g., Vibrio, Edwardsiella): Redness and swelling of the eyes, increased eye discharge.
Parasites (e.g., Diplostomum flukes): Crystal-like particles appear in the eyes, followed by redness and inflammation in the later stages.
3. Improper Care Practices
Overfeeding high-protein feed or sudden water temperature changes can trigger digestive disorders.
Long-term overuse of antibiotics may lead to internal organ damage.
II. Emergency Treatment Plan
1. Water Quality Adjustment
Immediately replace 1/3 of the tank water with temperature-matched, dechlorinated water, and raise the water temperature to 28-30℃ (82.4-86°F).
Add coarse salt (3-5g per liter of water) to regulate water osmotic pressure.
2. Fasting and Observation
Stop feeding the fish for 3-5 days to reduce the burden on its digestive system.
3. Medication Treatment
Bacterial Infections: Use yellow powder (0.1g per 50L of water) or gentamicin for a medicated bath.
Parasitic Infections: Isolate the infected fish immediately and completely clean the tank (including removing snails, as there is no specific medication for Diplostomum flukes).
III. Preventive Measures
Regular Water Changes: Replace 1/3 of the tank water weekly and maintain a pH level of 6.5-7.0.
Scientific Feeding: Avoid overfeeding high-protein feed; add probiotics to aid digestion.
Reduce Stress: Keep the water temperature difference ≤ 1℃ during water changes and avoid direct exposure to strong light.
IV. Precautions
Advanced-stage exophthalmia (where the eye detaches) is difficult to treat; it is advisable to remove the infected fish promptly to prevent further issues.
Do not mix multiple medications, as this may cause drug toxicity and worsen the condition.