Spironucleus - Hole in the head fish disease

Spironucleus - Hole in the head - Head and lateral line erosion fish disease

1. General description

The parasitic flagellates commonly live in the intestines mucosa of a freshwater fish. The presence of these parasites (their increase, number, etc.) is regulated by the immune system of the fish. Sometimes the flagellates can rapidly reproduce by binary fission when this immune system is weakened. The presence of flagellates reaches epidemic proportions and these parasites are transported to other internal organs of the fish (especially to the liver, kidneys and spleen) through its blood. The gradual destruction these organs leads to fish death.

2. Type of the disease

This is parasitic disease.

3. Cause of the disease

Causes of this disease are flagellates from Spironucleus genus.

4. Favorable circumstances for development of the disease

• weakened immune system
• stress induced by:
  - oxygen-poor water
  - high level of nitrites
  - rapid changes of the water temperature
  - too much fish in aquarium
  - mechanical injuries
  - careless handling of the fish
• contact the fish with contaminated feces or parasite cysts
• transfer the fish with help of an infected net

5. Common symptoms of the disease

• turbidity/ dulling of colours
• bloat the belly
• white, thin, sticky, jell like excreta which trail from fish anal vent, float in the water or lie on the bottom of the aquarium
• hole like skin lesions/ defects, especially around the head and along the lateral line
• loss of appetite
• tendency to remain in isolation from other fish, tendency to stay in corners of the aquarium

6. Types of the treatment

Metronidazole

This drug is in the tablets form. So we should crush and dissolve their in a small portion of warm water before their using. The dosage this medicine depends on a stage of the disease:

• the initial stage of the disease: we do about 30% water change and to increase water temperature up to 30°C before using the drug. Then we dose 250 mg the medicament per every 40 l (10 gallons) of the water in the aquarium. Next we do 25% water change after 8 hours and we repeat the dose of metronidazole (250 mg per every 10 gallons water). This cycle we repeat for 3 days,
• the advance stage or relapse of the disease: we do about 30% water change and to increase water temperature up to 30°C before using the drug. Then we dose 450 mg the medicament per every 40 l (10 gallons) of the water in the aquarium. Next we do 25% water change after 8 hours and we repeat the dose of metronidazole (450 mg per every 10 gallons water). This cycle we repeat for 3 days. We also give the drug with a food at the dose of 1 g per every 100 g food 3 times per day for several days. We feed fish small portions of food that after meal shouldn't remain in the water or on the bottom. We should also give the fish vitamins and microelements.

7. Comments about this disease

• It seems that discus and angelfish are very sensitive to this disease.
• Secondary infection this disease causes fish dropsy illness.
• We always remove activated carbon from a filter and we increase the aeration of the water before any treatment.

8. Prevention

• 4-8 weeks of quarantine for new fish,
• proper water parameters,
• a systematic partial water changes,
• enrichment of fish food with vitamins and microelements.