How do you handle requests from dog owners who don't want you to board another dog?

One way to handle it is to tell them that yes, you’re willing to book only their dog, and you have a different rate for exclusivity. That rate might equal your two dog rate. If dogs don’t have an issue getting along with other dogs most owners will say oh no that’s not necessary.

However with dog reactivity, carefully consider if you’re prepared for that challenge both when outside walking (passing external stimuli/ triggers) and inside your home (if you or any member of your family, including pets and children) will be endangered. As you might be able to conclude from my guidance, I will not accept canines with dog reactivity.

As a sitter you have accepted responsibility for all of the dogs in your care including the reactive one and the innocent bystander dog. The owner doesn’t want another dog around because as a responsible person they know their dog could cause damage or get into a fight it can’t win.

You can’t meet their requirements so the dog isn’t a good fit. If you want to keep the business I suggest explaining your circumstance to the owner, any crate and rotate protocols or separate yards and explain that you’ll need to increase the rate to account for missed revenue if they still choose to book.

It isn't their house.. I don't understand how they can make that request. Other than if they also book your second spot.