What do you do if you cannot get a hold of the owners for their pet's stay? They booked in August and I have tried contacting them since to find out details about the stay and cannot get a hold on them, what is the best thing to do?

It's great that you have ten days before the stay is scheduled. Since you haven't had success contacting them, I'd suggest contacting Rover Support, who may be able to connect with them (probably next week).

Definitely contact Rover. It may be they didn't set up text/email forwarding (or rarely check one or both), and they just didn't think to log back in until closer to the start of the stay. If you're calling/messaging their number directly they may have just ignored the unfamiliar number or have unknown numbers blocked. I wouldn't threaten to cancel the stay. If they aren't getting your messages, they won't see it anyway. Plus they've had over a month to cancel it on their own if that's what they wanted to do. All canceling it would do is prompt Rover to review, and potentially deactivate, your account. Plus, even if they do want to cancel, you stand to gain more by waiting, since you may get a portion of their payment if they cancel close to the start date.

I second contacting Rover, and giving notice. Did you have a Meet and Greet already?