In veterinary practice, buoyancy disorders are common in goldfish, often having a sudden onset and present floating at the surface or lying on the bottom. In my review of 47 goldfish cases in 2007, there were almost equal numbers of short-bodied and long-bodied goldfish. In many cases, there were no external lesions and no consistent environmental factors could be identified. Radiography was performed in 41 fish and proved the most useful investigative approach. Several radiographic abnormalities were found including over-inflation (44%), displacement (22%), fluid accumulation (12%) and rupture (2%) of the swim bladder and intestinal tympany (6%). Post mortem and histological examinations were performed on 34 goldfish: findings included systemic granulomatous disease (24%), abnormal fluid in the swim bladder (22%), polycystic kidney disease (18%) and several other internal diseases (22%). However, 16% of goldfish had no identifiable pathology and no consistent radiographic features. Most cases were euthanased on initial examination due to advanced disease but a quarter was treated conservatively. There was a very poor response to treatment and several environmental, medical, and surgical approaches are discussed. Since that review, I have examined further cases in an attempt to refine my approach to this common problem.
Ref: Wildgoose’ WH (2007) Buoyancy disorders of ornamental fish: a review of cases seen in veterinary practice. Fish Veterinary Journal (9), 22-27
William Wildgoose graduated from Glasgow Veterinary School in 1977 and has worked in small animal practice in London since then. He has a special interest in exotic pets and ornamental fish in particular, and obtained his RCVS Certificate in Fish Health and Production in 1997. He was a contributor and the editor of the second edition of the BSAVA Manual of Ornamental Fish in 2001 and has contributed chapters to several other veterinary text books on fish health.