KHV is a serious viral disease of fish and is a listed disease in the United Kingdom. It affects all varieties of common and ornamental carp species (Cyprinus carpio) and can result in large scale mortalities. Fish with KHV disease may show the following signs, especially when water temperatures are between 16 to 28 °C:
- necrotic (white or brown) patches on the gills
- rough patches on the skin and sloughing mucous
- sunken eyes
You must contact the FHI if you suspect an outbreak of KHV. This includes fish with the above signs, or deaths of carp or carp hybrids.
There is no risk to public health.
When laboratory testing confirms KHV disease at a site, the FHI place statutory controls to limit the spread of the disease. These controls restrict movement of aquatic animals and ensure equipment is disinfected.
Disease controls have been applied at:
Sites with KHV disease must undergo a formal monitoring programme for the duration of the calendar year immediately following the outbreak. The FHI visit these sites to look for evidence of disease and to inspect compliance with the conditions of the statutory controls in place. The controls are removed if the disease doesn’t reoccur during this period.
Some sites choose to cull and disinfect their stocks, rather than undergo monitoring.
Koi herpesvirus disease (KHV) is a listed disease under The Aquatic Animal Health (England and Wales) Regulations 2009. KHV outbreaks have been subject to statutory controls in the UK since 2007. The UK maintains a surveillance programme for this disease.
When the FHI confirm an outbreak, they take steps to control and, wherever possible, remove the disease. This may involve movement controls on susceptible species in the affected area, enhanced biosecurity, culling of fish, and cleaning and disinfecting of the premises.
Once statutory controls are in place the site operators must write to the FHI to get permission to move live fish into, out of, or within the designated area, and to make material changes to the site or site activities. This also applies to fish eggs and gametes.