Anesthetic Management of Goldfish (Carassius auratus) for Surgical Procedures in Tropical Settings: Practical Protocols for Low-Resource Veterinary Practice

Goldfish (Carassius auratus) are among the most commonly kept ornamental fish worldwide and increasingly present to veterinary clinics for surgical intervention, including tumor excision, swim bladder correction, fin repair, and abscess drainage. Despite this growing demand, practical, welfare-oriented anesthesia protocols for goldfish—especially in tropical, low-resource settings—remain poorly standardized in open-access literature. This narrative review presents a clinically applicable framework for anesthetic management of goldfish undergoing surgical procedures in tropical environments. Emphasis is placed on accessible anesthetic agents, particularly eugenol, with comparison to tricaine methanesulfonate (MS-222) where available. Anesthetic depth stages, dose ranges, induction and maintenance techniques, gill irrigation methods, monitoring parameters, and recovery protocols are described in detail. Special consideration is given to prolonged procedures exceeding 20–40 minutes, including dynamic depth control and emergency management. By integrating fish physiology, welfare principles, and real-world clinical constraints, this paper provides veterinarians with a step-by-step, low-resource anesthesia model for goldfish surgery. The objective is to improve surgical success, minimize anesthetic mortality, and promote humane handling of ornamental fish in tropical veterinary practice.