Control of therapeutic substances for animal use in Greece is the responsibility of the National Association of Drugs. Imports of such drugs as well as circulation within Greece is in the hands of this Association and all drugs in use have to be specifically licensed in Greece. Such licensing follows EEC guidelines and involves a requirement for testing of purity, toxicity, metabolism, residue studies, bioavailability, safety, etc. Such compounds are readily provided by the major pharmaceutical companies for the common domestic animals. Unfortunately, such compounds for fish use are very limited in number and throughout Europe at present only include a potentiated sulphonamide (Tribrissen), an oxytetracycline (Terramycin) and certain quinolones (oxolinic acid and flumequil). The latter group of compounds is not yet available in Greece. Commonly used compounds such as formalin, malachite green and surfactant agents are not licensed but are in use.
Prescription of antimicrobials such as those mentioned above has to be undertaken by a veterinary surgeon, often one of the veterinarians involved in fish disease diagnosis at one of the laboratories of the Ministry of Agriculture (Vet. Division), and 40% of the cost of such medicines is subsidized by the Government.
In cases of necessity, for instance resistance of fish pathogens to the two available antibiotics, non-licensed or generic compounds can be imported by the National Pharmaceutical Company, a public body, but with strict control from the National Organization of Drugs on import and subsequent use of the drugs.
Mixing of drugs for in-feed medication either at food mills, or more commonly, on the farm, is not controlled by legislation.
No specific requirements in terms of withdrawal periods and residue testing exist for fish in Greece at the present time.
Suggestions for Future Improvements
There is a major EEC exercise at present in standardizing control over therapeutic substances for animal use and Greece will be required, as a member state, to follow those requirements. Specific requirements have been made for licensing the incorporation of in-feed medication for other animal species, considerably restricting on-farm mixing and the use of non-licensed products. However, despite long-term discussions, the situation has not been resolved for fish therapeutics. Nevertheless, when guidelines are issued, Greece will be expected to follow EEC recommendations.
The principal problems are as follows:
1. Very few licensed compounds are available because of the relatively small size of the aquaculture industry. Pharmaceutical companies are unwilling to license compounds at vast expense which will produce limited financial returns. Those compounds that are licensed for trout and occasionally salmon. No licensed compounds exist for bass, bream, eels, etc.
2. Because fish are poikilothermic animals, feeding rate varies with temperature. This means that dietary incorporation rate of antibiotic per kg bodyweight varies considerably and “standard” mixed supplies cannot be held “on the shelf”. The result is that almost every treatment has to be given by handmixing of antibiotics on the farm. Delays in food mill-mixing and delivery would result in serious escalation of the disease problem, inappetance and thus ineffective treatment. Licensed mixing is therefore not practical.
The end-result has been that, at present, fish are exempted from current regulations and in practice, generic compounds are commonly used without specific fish licensing. Such will be the most efficient way of controlling fish disease in Greece at the present time.
In the UK, Schedule 1 of the Animal Health Act 1981 (Appendix 2) is particularly concerned with veterinary therapeutic substances. Of particular significance is section 3 (3) which allows a veterinary surgeon to use non-licensed substances “for the treatment of any animal under his care”. This ensures that the veterinary surgeon involved in prescribing the treatment is closely involved with the clinical diagnosis and makes practical, the treatment of fish disease.
In terms of avoidance of residues from the use of such nonlicensed compounds, the UK regulations require a 200 degree day withdrawal period for any non-licensed compound before fish may be used for human consumption.
It is suggested that legislation in Greece on withdrawal periods and non-licensed compound use in fish be established on a similar basis as a temporary measure until EEC guidelines are produced.