My horses don't get a vacation. They are used to work nearly every day. Every once in a while they will get a day or so off, sometimes more, if I have a young or different horse to ride that day. It doesn't bother them because they are used to the work and the schedule. This last spring I was away from home for about 2 weeks. When I came back, the horses were more than ready to go back to work.
The time that I like some time off for them is with my young horses. They are typically started as 2 year olds in the fall when the weather cools off. They get about 45-60 days riding, then are turned until March or April or so. Then as three year olds they seem to be a lot more willing, learn quickly, and start to really love to work. Those few months gives them time to mature physically and mentally, and finish 'growing up' out of that gangly teenager stage.
American by birth. Cowgirl by the grace of God. And I wouldn't have it any other way.