In the autumn of 2013 Koi Sleepy Disease (KSD) was detected for the first time in the Netherlands in diseased koi from a large pond in the centre of the country.
The disease was spotted by CVI and confirmed by CEFAS (United Kingdom) in their PCR test. Koi Sleepy Disease has been described since the mid-seventies in juvenile koi in Japan, and is caused by carp edema virus (CEV). CEV is a pox-like virus, that may cause koi disease at low water temperatures (13-23°C). The virus is harmless to humans. The first cases of KSD in Europe were detected in 2011 in the UK. Since then the disease has been spotted in 2013 in France and in the Netherlands.
Koi with Koi Sleepy Disease show apathetic behaviour and symptoms similar to those of Koi Herpes Virus disease, such as sunken eyes and gill necrosis. A significant difference in case of KSD is that older koi will lie on the bottom and die within a few days. Even though the disease has been known in Japan since 40 years, in Europe only a few cases are known. There is no therapy for Koi Sleepy Disease. The best policy is to buy disease free koi and keep koi from different sources separate.
Olga Haenen, Keith Way, David Stone en Marc Engelsma, 2013. Koi Sleepy Disease (KSD) door 'Carp Edema Virus': eerste detectie in Nederlandse koi. Aquacultuur 5: 27-29.