Does an electric fence need to be a complete circle?
No. An electric fence circuits flow relies on passing through a conductive object (usually an animal) and into the physical earth or ground itself (as shown in this picture). This earth return path for the electrical flow can also be achieved with an earth wire. The animal should act as the connection between these two wires (live and earth). Vegetation can also connect the circuit between both wires or live wire and ground soil resulting in power loss further down the fence line, this is generally called shorting out.
You can however branch new fence wires off the main fence line to run new sections of fence at any given point while only the one connection to the main wire is required at the joining end (like a T shaped branch off). So an electric fence does not have to make a complete loop to be an effective barrier or an effective circuit. If you dont need to, dont make a loop in your electric fence as it becomes more effective overall most of the time, If you have to make a completed or fully joined electric fence circuit it should still function effectively. Test should be carried out whenever erecting or changing the setup of an electric fence.
Due to the nature of return paths for electric fence power flow, special care should be taken into account for the condition and conductivity of the ground and soil around the fence and the quality or need of installation of earth wires to assist in creating an effective return path for your electric fence.
Does an electric fence have to make a complete loop?