Several aquatic retailers in the UK have undertaken culls of certain coldwater fish after the deadly fish virus SVC was found in imported goldfish.
As reported by Practical Fishkeeping last month, officials from the Fish Health Inspectorate confirmed that spot checks on imported goldfish had revealed the presence of Spring Viraemia of Carp (SVC) in a shipment of goldfish brought into the country from the Tung Hoi Aquarium Company in Hong Kong. (See Deadly fish virus found in imported goldfish).
The shipment was imported on February 19, but it wasn't until March 3 that the lengthy diagnostic tests revealed the presence of the virus.
By that time, 16 boxes of fish from the same supplier had been shipped to one consolidator and 20 aquatic retailers who may have mixed them with their own stock and started selling them to the public.
A Fish Health Inspectorate spokesman told Practical Fishkeeping: "Upon positive identification of the virus the importer was notified immediately and a list of all premises that had received species susceptible to SVC from the same shipment was complied.
"All the premises that had received any such fish were placed under movement controls and samples taken from the sites by the FHI.
"The FHI also provided advice to other businesses, which may have recently imported fish from the same source, to increase awareness of the potential SVC risk."
Movement controlsDiagnostic tests to confirm the presence of SVC in fish can take a minimum of two weeks, and during that time the business affected is placed under movement controls which mean that they cannot move or sell any susceptible species from their premises.
According to the FHI, some dealers who had been placed under movement controls, preventing them selling or moving fish, opted to remove the risk of transfer or spread of the disease by culling their coldwater fish, rather than waiting for the test results to confirm whether the fish had SVC or not.
"These premises were assisted and supervised by the FHI in the humane destruction and disposal of the compromised stocks, and in the disinfection of the systems that had held the stock.
"The disinfectants used were in accordance to FHI recommendations. Once the premises were satisfactorily disinfected controls were lifted and normal business was allowed to resume.
"It should be noted that throughout the investigation all of the businesses affected cooperated fully with the FHI s investigations, and demonstrated a professional approach and commitment to the control of the disease."
Other businesses, which had large amounts of valuable fish, opted to wait for the tests to be completed in order to ascertain whether any of their fish had come into contact with the virus, thereby preventing needless culling of uninfected stock.
During this period those dealers were unable to trade in any of the susceptible species.
Those movement controls were subsequently lifted on sites that tested negative for SVC.
Previous importsDealers who had purchased fish from Tung Hoi in previous shipments were contacted and warned that the fish they had purchased may have been exposed to the virus.
They were also informed of the legal requirement to inform the FHI of the deaths of any carp, goldfish or other SVC susceptible species that might be attributable to the disease.
The FHI told Practical Fishkeeping: "The authorities in the exporting country were informed of the isolation of SVC and they are conducting investigations to identify the source of the infection. Importation of fish from the affected source will be prohibited pending the conclusion of these investigations.
"A shipment from Tung Hoi was tested for SVC earlier in the year, which was negative.
"Anyone who imports, keeps or retails carp or other species susceptible to SVC should take strict precautions to prevent the introduction and spread of the disease.
"Advice is available in Defra's booklet "Keep Fish Disease Out", available from the Fish Health Inspectorate based at Cefas or through www.efishbusiness.com
The virus causes clinical signs including darkening of the skin, swollen eyes, abdominal swelling, pale gills, trailing faeces and protrusion of the anus. Infected fish can also be lethargic and may show areas of bleeding around the skin and gills.
SVC affects common and ornamental Carp, Goldfish, Tench, Rudd, Pike and Wels catfish.