Hats off to you Candy! What a great idea!
Since you'll be learning something you already know a lot about, going back to school won't be so hard. As Jackie said: "You only have one life to live," and you'll be doing something you love and are good at. It beats being locked up with main frame computers any day.
Doggie day care places are becoming very popular with people who work long hours and I'm sure you'll be very successful.
Good luck.