In all bacterial diseases in fish, the surrounding environmental conditions can influence the uptake, colonisation and establishment of the bacterial diseases within the susceptible fish species because fish are reliant on their environmental conditions to support their homoeostasis and sub-optimal or variable conditions. There are few studies reporting the range of environment factors and how these have contributed towards the development of S. agalactiae infection in tilapia. Among the conditions that were suspected of favouring this disease were high water temperature, low dissolved oxygen (DO) and the weight and / or the age of fish.