Water & environmental problems
Gas bubble disease
Water supersaturated with dissolved gases can cause gas bubble disease. It is different from simply having visible bubbles from an air stone.
When to suspect a system issue
Unexplained distress after a water-supply or plumbing change needs investigation. Tiny bubbles in tissues, eye changes or buoyancy problems can have multiple causes.
Check the equipment history
Tell the specialist about well water, recently altered pipes and possible air being drawn into pressurised lines. Oxygen and temperature should be assessed at the system.
Do not puncture anything
Have the cause confirmed and the water system corrected. Do not attempt to release bubbles from a fish with a needle.
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.