Koi Sleepy Disease: Emerging Fish Disease from Japan
How often might imported Japanese koi that are introduced into concrete traditional koi pond suffer from these Koi Sleepy Disease that is found where they are moved from mud ponds to concrete ones?
Histopathological and electron microscopy studies on sleepy disease of koi Cyprinus carpio koi in Japan.
Miyazaki, T., Isshiki, T., Katsuyuki, H.
Author Affiliation: Faculty of Bioresources, Mie University, 1577 Kamihama, Tsu, Mie 514-8507, Japan.
Diseases of Aquatic Organisms, 2005 (Vol. 65) (No. 3) 197-207
Koi sleepy disease (KSD) usually occurs when koi Cyprinus carpio koi are taken from nursing earthen ponds and placed in cement-lined ponds containing fresh water in spring and autumn in Japan. We transferred koi from an earthen pond to tanks containing fresh water and 0.5% salt water in an attempt to replicate KSD and prevent the onset of KSD, respectively, in the laboratory. KSD broke out after 4 to 5 d, followed by mass mortality (76%: 95/125 fish) within 17 d, in the fresh water. Diseased fish died within a few days. Examination revealed enlarged cells in the respiratory epithelia of gill lamellae; hyperplasia of interlammellar epithelia resulted in clubbing of gill filaments, which caused hypoxia when severe. Electron microscopy showed that enlarged cells contained immature particles (416-450 nm diameter) or mature virions (333-400×400-413 nm) of a pox-like virus in the cytoplasm. Mature virions were transported to the periphery of the cells. Hepatocytes, renal tubular epithelial cells, muscle cells of the lateral musculature and cardiac muscle cells were cloudy with mitochondrial degeneration. PCR assay using primer sets for a pox-like virus causing ‘carp edema’ determined that KSD-virus is the same as the carp edema virus. None of the koi held in 0.5% salt water showed sleepy disease during a 25 d experimental period; PCR assay revealed no KSD-virus in gills of koi in the same treatment.
KSD was the subject of lecture along with KHV at the Sept. 2006 5th International Symposium of Animal Health.
Emerging diseases
P. Dixon described the occurrence of viral diseases in cyprinids as rhabdoviruses, KHV, CyHV-2, Koi sleepy disease and aqua reoviruses. Placing hosts in new environments might lead to new viral infections. Better diagnosis and access to better diagnostic tools would also lead to a greater awareness amongst farmers. Global warming and changed management practices (such as overcrowding) might also play a part.
http://www.thefishsite.com/fishnews/4058/highlights-of-the-fifth-international-symposium-of-aquatic-animal-health
This is truly a shame that koi are suffering from this kind of sickness. Now how can we stop people from changing koi from their natural enviroment to concrete ponds?
I RESENTLY BOUGHT 5 AMERICAN KOI. RESENTLY TWO OF MY JAPPANESE KOI HAVE DIED. IS THERE A DISEASE AMERICAN KOI ARE RESISENT TO THAT JAPANESES KOI ARE NOT?