Swim Bladder Disorder

When to act urgently

Breathing distress, rapid deterioration, inability to remain upright, major wounds or multiple deaths require urgent aquatic-veterinary or fish-health help. Check aeration and water immediately; do not wait to match a photograph.

What you may notice

• Difficulty staying level, floating, sinking or repeated loss of posture.

Possible causes and look-alikes

• Water stress, diet-related gas, structural abnormalities, injury and internal disease can cause similar behavior.

Check first

• Record species, aquarium type, recent arrivals or changes, appetite, breathing, and how many fish are affected. Check aggression, injuries, filtration and aeration.
• Test ammonia, nitrite, pH and temperature; measure dissolved oxygen where possible and salinity in marine/brackish systems. Correct verified environmental problems using suitably prepared water, avoiding abrupt chemistry changes.
• Check whether the fish can reach food and whether exposed or resting skin is being injured.

Treatment and correction context

• Persistent loss of posture or damaged skin needs veterinary assessment; imaging may be needed to investigate internal structures.
• A universal fasting, pea, salt or antibiotic recipe is inappropriate. Support and treatment depend on the species and identified cause.

Record for your next step

Write down onset and progression, species, affected/total fish, recent introductions, feeding observations, dated water results with kit units, and every action or product already used. Contact the diagnostic service before collecting or shipping samples.

Sources and scope

Source checks: 2026-10-03. Educational editorial summary; no independent veterinary review.

• Fish Vet: Swim Bladder Disease

  Specialist veterinary education on buoyancy causes and diagnostic assessment.

• UF/IFAS: Submission of Fish for Diagnostic Evaluation

  Case history and contacting a diagnostic service before collecting samples.