Under pressure: Use of hyperbaric chamber therapy for management of dissolved gas disorders in fish-15 cases...

Our objective was to describe clinical findings, treatment protocols, and outcomes in captive fish presenting with ocular and/or buoyancy disorders attributed to dissolved gas disease undergoing novel treatment with hyperbaric therapy.

Electronic medical records were reviewed for 15 teleost fish comprising 10 species housed at a public aquarium and treated between 2015 and 2025 with hyperbaric chamber therapy for exophthalmos (n = 8), intraocular gas (n = 5), buphthalmos (n = 5), and/or positive buoyancy (n = 7). The collected data included diagnostics, adjunctive therapies, hyperbaric chamber course and parameters, response to treatment, recurrence, and postmortem findings when available.

Initial clinical improvement in response to hyperbaric therapy was documented in 10 (67%) of the 15 fish, with long-term resolution (1 month: n = 1; 5 months: n = 1; >18 months: n = 5) of clinical signs observed in 7 (47%) of the 15 fish. Three fish (21%) died during chamber treatment. Necropsy and histopathology identified infectious comorbidities in multiple nonresponders (n = 6).

Hyperbaric chamber therapy was associated with meaningful short-term (instantaneous to <12 h) clinical improvement in many fish, particularly those with ocular presentations. Recurrence and mortality were common, most often in cases with severe and/or comorbid disease. Hyperbaric therapy may be a viable modality for the treatment of dissolved gas disorders and warrants further investigation.