Changes

==Clinical Signs==

==Clinical Signs==

Affected fish have '''marked ascites giving them a pot-bellied appearance, show exopthalmos and have multiple haemorrhages of the fins and musculature'''. The '''vent may be swollen''' and protrusive and the gills pale. Opercular movements are often increased. Affected fish may seem to be '''off balance, swimming erratically''' or close to the surface and eventually sinking to the bottom. Up to 50% of moribund fish may '''hang head upwards''' at the surface.

Affected fish have '''marked ascites giving them a pot-bellied appearance, show [[Exopthalmos - Fish|exopthalmos]] and have multiple haemorrhages of the fins and musculature'''. The '''vent may be swollen''' and protrusive and the gills pale. Opercular movements are often increased. Affected fish may seem to be '''off balance, swimming erratically''' or close to the surface and eventually sinking to the bottom. Up to 50% of moribund fish may '''hang head upwards''' at the surface.

Fish that survive CCVD have '''strong protective immunity for the remainder of their lives but remain in a covert latent carrier state''' which is undetectable antigenically and difficult at best. This is a significant source of disease for vulnerable fish. It is unclear how these fish shed the virus.

Fish that survive CCVD have '''strong protective immunity for the remainder of their lives but remain in a covert latent carrier state''' which is undetectable antigenically and difficult at best. This is a significant source of disease for vulnerable fish. It is unclear how these fish shed the virus.