An assessment of disease status in Greece is hampered by a lack of regular examination of stocks and a lack of specific microbiological facilities and is likely therefore to contain a number of gaps. The fact that particular diseases have not been reported does not necessarily mean that they are not present.
Information is principally available on freshwater fish diseases, with the first readily-available published report being that by Ghittino and Pneumatikatos, entitled “Stato attuale, possibilità e problemi sanitori della piscicoltura greca 1977” published in Riv. It. Piscic. Ittiop. A XII. N.4. (1977) pp. 101–107. The report was based on a survey conducted in March 1977 under the UNDP/FAO project FI: GRE/76/002/1. Conditions described were:
It will be immediately apparent that these diseases are either of environmental (a, e, g), nutritional (b, f, h) or parasitic (c, d) origin and reflected problems with water quality, poor nutritional quality due to trash-fish feeding, incorrect pelleted food storage and individual parasitic diseases.
Discussions with the veterinary surgeons involved in fish disease work at present indicate that parasitic diseases (e.g., a range of ectoparasitic protozoa and monogenetic trematodes) are particularly common but relatively easily treated. Nutritional diseases, either gross fat oxidation problems or vitamin deficiency problems, are still present but probably not so severe as in 1977 and water quality problems still exist in certain sites with poor basic water supplies. In carp culture carp erythrodermatitis has been frequent, possibly associated with Spring Viraemia, though no virology has ever been carried out. Eel culture is affected by a range of bacterial, parasitic and fungal problems and losses still occur in all species through physical handling problems and other non-infectious agencies.
In marine species, bacterial disease has been relatively common, especially with Vibrio infections, serious losses have occurred through storm damage, and parasitic infection is relatively common. Numbers of bass and bream are affected with spinal deformities and lack of swim-bladder development.
As long ago as 1965-7, serious losses occurred in the trout industry thought to have been possibly due to IHN or VHS, but eradication of stocks occurred and no obvious clinical outbreaks of such diseases have occurred since. However, no viral examinations have ever been undertaken. No specific diagnosis of furunculosis (A. salmonicida infection) or redmouth disease (Y. ruckeri infection) has ever been made.
Recently, Bothriocephalus infections have caused problems in carp. The source of the infection is unknown, but imports of carp had occurred just previous to the problem developing.