Leaving 9 month old for a month

I am going to be volunteering this summer out of the country for a little over a month. My wife is nervous about this because I am always the one who controls our hellhound, Luka. I take him for walks. We play fetch. I take him down to our duck blind to run. My wife is going to have to take on some of those responsibilities, and she is very nervous. She always walks our poodle who is very well-mannered. Does anyone have any advice that I could pass on to her.