How will I know which daycare is the best one for my dog?

Ask questions.  Visit multiple facilities.  Talk to the manager and staff, and go with your instincts.  Is the environment calm and controlled? Do the dogs seem stressed or happy?  Are the staff members interacting with the dogs? If not, they can’t know them well enough to detect or avoid trouble.  Is the daycare sufficiently staffed? Does the daycare have a screening process? If they don’t demand proof of vaccinations from you, they aren’t requiring it of anybody else.  Does the daycare have a relationship with a vet that is close by? Are there specific strategies in place for handling problems as they arise?