Fish quarantine: current practices in public zoos and aquaria

The primary goal of quarantine is to reduce the risk of introducing infectious diseases into established collections. Fish quarantine is inherently complex because of the variety of species, environmental requirements, and facilities. To examine current practices, questionnaires were submitted to 60 public zoos and aquaria, predominantly in North America. Questions reviewed system type (closed, flow-through), quarantine length, diagnostics, treatments, and cleaning and disinfection. Forty-two of the 60 institutions responded. Most institutions had separate quarantine protocols for freshwater teleosts, marine teleosts, and elasmobranchs. Ninety-five percent of institutions had a minimum quarantine period of 30 days or more. Sixty-four percent of institutions used isolated areas for some or all of their fish quarantine. Twenty-five percent had designated fish quarantine staff. All institutions used regular visual examinations to assess animal health. Fifty-four percent of the institutions carried out routine hands-on diagnostics on some fish; this was more common for elasmobranchs than teleosts. All institutions carried out necropsies on mortalities. Fifteen percent of institutions performed histopathology on almost all fresh mortalities; 54% percent performed histopathology on less than 10% of mortalities. Prophylactic treatments were common in closed systems, in particular, formalin immersion for teleosts, freshwater dips and copper sulfate immersion for marine teleosts, and praziquantel immersion for marine teleosts and elasmobranchs. Institutions using dips generally did so at the start or end of quarantine. Fenbendazole- and praziquantel-medicated foods were used commonly in teleosts, but dosages varied greatly. Cleaning and disinfection of systems and equipment increased in response to known pathogens. These results can be used to compare and discuss fish quarantine practices at display facilities in order to improve quarantine success.