Thyroid neoplasia associated with nutritional deficiency in cultured jade perch in Hong Kong.
Stephen C H Chan, Zwok Zu Lim, Aaron C F Leung, Tzu Hsuan Cheng, Ka Po F Cheng, Sophie St-Hilaire, Andrew M D Ferguson
Author Information
Stephen C H Chan: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Zwok Zu Lim: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Aaron C F Leung: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Tzu Hsuan Cheng: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Ka Po F Cheng: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Sophie St-Hilaire: Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China.
Andrew M D Ferguson: CityU Veterinary Diagnostic Laboratory, City University of Hong Kong, Kowloon Tong, Hong Kong, SAR China. ORCID
Non-neoplastic thyroid hyperplasia is common in terrestrial animals, secondary to nutritional imbalances or other goitrogenic compounds. Thyroid hyperplasia is relatively common in teleost fish; however, malignant thyroid neoplasia is rarely reported. We diagnosed cases of thyroid neoplasia in a population of jade perch (). The 3,000 affected fish had grossly apparent, bilateral pharyngeal swellings. Histologic examination confirmed proliferative thyroid lesions ranging from hyperplasia to well-differentiated follicular cell carcinoma. In addition, the younger population of animals on the farm also had bacterial septicemia and mild sp. gill infections. Feed analysis revealed a severe deficiency of iodine and vitamin C in the homemade fish diet used on the farm. The concentrations of other minerals, such as zinc, were also on the lower end of the recommended requirements for freshwater fish. The farm was using surface water in its recirculating aquaculture system. We recommended a switch to a commercial aquaculture diet, as well as to use well water rather than surface water to avoid any contaminants, and to treat the younger fish with an antibiotic for bacterial septicemia. Our case provides evidence of progression from nutritional-associated thyroid hyperplasia to neoplasia in farmed teleost fish.
