We have had Brooke (Lab cross) since February this year. She is a rescue dog. We generally feed her at the same time in the evening's. I usually walk her about an hour and an hour after her evening feed. The last two nights she hasn't poo'd. I worry that she should not go all night without her toilet. I am reasonably happy that she would make some noise if she needed to go as her manners are superb. Am I over worrying or is this common amongst dogs?