[The dynamics of the immunologic indices of carp exposed to methylene blue]

Several immunological and haematological indices as well as infection of carp with ectoparasites of the Dactylogyrus genus have been studied in fish that have been subjected to methylene blue treatment, to infection with Rhabdovirus carpio and Aeromonas hydrophila in different combinations. A dosage of 0.05 mg/l (exposure lasting for 3 days) over 20 days increases most of the immunological indices. A treatment of the carp with drug (dosage of 100 mg/l) for 4 hours has a stimulating effect on the immune system over a period of 40-60 days. The infection of the carp with virus immediately after the drug treatment (dosage 100 mg/l) gives rise to a disease of a certain part of fish. In connection with this a problem on terms of the methylene blue treatment is discussed taking into account the development of the disease.