When you no longer want to house sit for someone, send along a letter like this to let the homeowner know they need to make other arrangements.
I need to let you know that I can't housesit for you anymore, after this coming weekend we already had scheduled.
I'll be picking up my new puppy next week and he will need me home overnight, at least for the time being.
There are a few people I could recommend; just let me know if you'd like some names.
