The meaning of trough in dream | Dream Interpretation
An animal quenching its thirst at a trough is a symbol of tranquility and the announcement of good news, especially financial. On the other hand, if the trough is dry it means you are about to experience a loss of capital.
If you are the one drinking from it you should deduct that is not the best place to satisfy your thirst, and you will have to change the methods you employ to meet your needs in real life. That indicates, therefore, that you must seek other sources more appropriate for drinking.
According to tradition, dreaming of a trough predicts an inheritance is coming soon.
If it seems dirty it indicates a child will be born soon; if it is dry, it indicates some mysteries will be unveiled; and if horses are drinking from it, future happiness.