To study the prevalence of ectoparasites and their clinicopathological effects on backyard poultry, 300 poultry of both sexes and different ages were examined in different areas of Patuakhali district from July 2005 to May 2006. Of them 86.67% were infested with one or more species of ectoparasites. Six species of lice such as Menacanthus stramineus (74%), Menopon gallinae (63%), Lipeurus caponis (48%), Cuclotogaster heterographus (25%), Goniodes gigas (18%), and Goniocotes gallinae (14%), two species of mites namely Dermanyssus gallinae (57%), Knemidocoptes mutans, (43%) and one species of fly, Simulium sp. (3.7%) were identified. Among these, M. stramineus was the most common. Aged above 5 months, 100% poultry were infested with ectoparasites but cocks and broody hens were severely infested. In broody hens, prevalence of D. gallinae was the highest (97.3%). K. mutans (43%) was mostly found in adult poultry aged above two years. The affected birds were emaciated with rough plumage, dandruff, and petechial haemorrhages on the highly infested skin. Small ulcerative lesions were common in Dermanyssus gallinae infestation in which the engorged, red parasites stacked tightly. In K. mutans infestation, legs were rough, swollen with scaly appearance, which was from tibiotarsal joint downwards to the joint of the toes. Some of the severely affected birds showed lameness but no malformation was observed. Histopathologically, scaly leg was characterized by hyperkeratosis and acanthosis. In tissue sections, the mites were observed as transverse or cross section in the deeper parts of the stratum corneum or the superficial layers of the stratum malpighii of the skin and rarely go deeper. In some area of skin, there were losses of epithelium. In advanced cases, there was secondary pyogenic infection; characterized by severe pus cell infiltration in the dermis. The present study suggests that ectoparasitic infestation is very common in the backyard poultry of Bangladesh and they are associated with the production of some clinicopathological effects variable degree.

Livers (n = 80) of slaughtered adult buffaloes were examined for pathological changes during the period from July 2006 to March 2007 in two slaughterhouses of Barisal district. Livers exhibiting gross alterations were cleaned with normal neutral saline and the changes were recorded. The lesions containing tissue samples were collected in 10% buffered formalin for fixation. Grossly, Gigantocotyle explanatum infection (amphistomiasis) was found in 31.25% and Fasciola gigantica infection was in 22.5% cases. Hydatidosis (2.5%), abscesses (3.75%), and haemorrhages (2.5%) were found in the liver. Histopathologically, cirrhosis was found in 31.25% cases. Nodular hepatitis 7.5%, granulomatous hepatitis 5% and parasitic cholecystitis 15% were also recorded during the investigation. Survey showed that the severity of infection with G. explanatum 31.25% and F. gigantica 22.5% and cirrhosis 31.25% were of highest percentage.

To study molluscicidal effects of some indigenous plants such as Dhol Kalmi (Ipomoea fistulosa), Lantana (Lantana camara), Rakta-karabi (Nerium indicum), Polash (Butea frondosa), Mohavringoraj (Wedelia calandulacea), Nishinda (Vitex negundo), Bishkatali (Polygonum hydropiper), Kalmi, (Ipomoea aquatica), Haicha ( Alternanthera sessilis) and Shaora (Streblus asper) were used as dusts, aquatic, ethanol and methanol extracts against Lymnaea auricularia, Lymnaea luteola and Indoplanorbis exustus to give in vitro trial from January 2006 to December 2006 in the Department of Parasitology, Bangladesh Agricultural University, Mymensingh. All the plants in all preparations were more or less effective against the treated snails. In this study, LD 50 , Min.C s100 and mortality percentage of fish (Gutum, Letidocephalus guntea, Family: Cobitidae) were determined using dust of the selected plants. LD 50 was minimum in case of Haicha (14.3mg/L) followed by rakta-karabi (29.25mg/L), bishkatali (46.88mg/L), kalmi (154.69mg/L), lantana (234 mg/L) etc. Min.C s100 was minimum in case of rakta-karabi (0.008%) followed by haicha (0.03%), lantana (0.06%), dholkalmi (0.25%) and kalmi (0.25%). Among the plants, lantana, haicha and kalmi had no lethal effect on fish at Min.C s100 . Shaora also had no toxic effect on fish but its both LD 50 (453.13mg/L) and Min.C s100 (1%) were very high. Present study suggests that dust of haicha, lantana and kalmi may be used @ 0.03%, 0.06% and 0.25% respectively to control snails in field level.