Internal parasites
Capillaria and other intestinal nematodes
Capillaria-type nematodes can be investigated when fish lose condition. Symptoms alone cannot identify the worm.
A sample can help
Characteristic eggs may be sought in appropriate material. A clean skin scrape does not rule out an intestinal problem.
Give a feeding history
Record the fish’s appetite, the diet and whether it is being outcompeted. Collect samples only as directed by the examiner.
Treat a finding, not a guess
Ask for the exact diagnosis, route of treatment and recheck plan. A medicine for external parasites may not address an internal infection.
Sources & further reading
Original WakeyKoi wording, informed by the references below. Linked clinical resources explain the evidence and their scope; they have not reviewed or endorsed this website.
Related guides
Educational guidance cannot diagnose an individual fish. Breathing distress, severe injury or unexplained losses need prompt professional assessment.