The health safety of the waters of the Danvali Valley and the Tigris river in Mosul city for watering livestock and poultry were studied. Samples were collected from ten sites and at a rate of one sample per month from October 2020 to November 2021 to measure each of the physical, chemical and biological properties according to international standard methods with the application of the weighted sub-index (WQI) model for water quality assessment. The results indicated that the WQI values of the valley water increased to reach (937.9, 1198, 1146, 10386) during the winter, spring, autumn and summer seasons consecutively. Thus, the waters of the valley and the Tigris River are from the category of water unfit to very poor for watering livestock and poultry. The deterioration in quality is mainly attributed to the high organic load of the waters of the valley and the Tigris River, which amounted to (8-19.2) (2.7-12.2) ppm, as well as the number of faecal coliform bacteria ranged between (158-778) and (146-777) cells. 100 ml-1 consecutively. The study recommended not to use water for irrigation of livestock and poultry because of its negative impact on animal health and productivity.