Compare swelling with the fish’s normal shape
A round fancy goldfish is not necessarily bloated. New enlargement, asymmetry or a sudden change in appetite is more concerning. Eggs and digestive fullness are possible explanations, but they should not be assumed.
Dropsy and raised scales
Dropsy describes fluid accumulation rather than a single infectious disease. Scales that stand out like a pine cone can accompany serious internal illness. Contact an aquatic veterinarian promptly, especially with lethargy or breathing difficulty.
Do not diagnose constipation from appearance alone
A swollen belly or long waste strand does not prove constipation. Review portions and diet, but avoid repeated fasting, salt dosing or medication as a substitute for assessment. Test water and prepare observations of onset and progression.
When to get professional help
Seek urgent help for severe breathing difficulty, bleeding, raised scales or inability to stay upright. Record exact water results and recent changes. A separate hospital aquarium must also be adequately filtered and aerated; an uncycled bowl can make the problem worse.
Frequently asked question
Should I medicate before testing the water?
Check water and oxygen promptly. Treatment should follow the likely cause; avoid mixing remedies without qualified guidance.
Sources and further reading
General husbandry and health references. Individual fish and local conditions vary.