Studies were conducted to investigate ulcer type of disease in the small-scale rural poor fish farmerís pond and to suggest a low-cost treatment measure. In total 20 ponds of 10 different sites were selected in the district of Mymensingh for treatment and control ones. Fishes were sampled on monthly basis starting from September 2000 and continued until April 2001 to examine their disease condition. Ulcer type of disease with expression of lesions was detected by spot observation followed by laboratory examination. A number of suspective bacterial pathogens were recovered from the lesions and kidney of diseased fishes, viz., Cirrhinus cirrhosus, Labeo rohita, Catla catla, Barbodes gonionotus, Pangasius hypophthalamus. Fungal isolates especially Aphanomyces sp., Saprolegnia sp. and Achlya sp. were recovered from the lesions and affected muscles of the sampled fishes. A number of recovered bacterial isolates were detected as pathogenic among which Aeromonas hydrophila, Ah-11 and A. veronii biover sobria were recognized as high virulent isolates. In the case of fungal isolates Aphanomyces sp. and Saprolegnia sp. were detected as pathogenic. Prevalence of disease outbreak was found to be very low where preventive treatment measures were taken with salt and lime (1:1, 1 kg/decimal). In the winter months (January and February), the disease outbreaks were found to be very high in the non-treated (control) ponds, whereas in the treated ponds prevalence of infection were significantly low. In laboratory based treatment trial, antibiotic renamycin was found to be effective against bacterial invasion at a dose of 50mg/kg body wt/day applying for five days. In the case of fungal infection, the diseased fishes were found to be cured within five days by one hour bath in 0.5% salt and lime suspension at a ratio of 1:1 applying for 3 days.
M.B.R. Chowdhury , M. Muniruzzaman , U.A. Zahura , K.Z.A. Habib and M.D. Khatun , 2003. Ulcer Type of Disease in the Fishes of Small-Scale Farmer`s Pond in Bangladesh. Pakistan Journal of Biological Sciences, 6: 544-550.