EN
Gram-negative bacteria isolated from the abattoir effluent on surface water of River Katsinaala in rainy and dry seasons were Escherichia coli; Klebsiella spp; Proteus vulgaris; Salmonella typhi and Gram-positive bacterium isolated was Streptococcus faecalis. In rainy season, the lowest mean bacterial count was from E.coli (0.0067+0.031 CFU/ml) and highest mean bacterial count from Salmonella typhi (0.0262+0.0079 CFU/ml). In the dry season, lowest mean bacterial count was from Proteus vulgaris (0.0081+ 0.0047 CFU/ml) and the highest from Streptococcus faecalis (0.0097+ 0.05 CFU/ml). The presence of Escherichia coli indicates possible faecal contamination. The results revealed that bacterial load was within the accepted maximum limit by WHO (2004); nevertheless, the disease causing bacteria pose threat to human health when water from the river is consumed without treatment.