Look for vigorous screening, supervision, and separation of big/small dogs. Ensure adequate staffing levels.
Well-trained staff knowledgeable in dog behavior and health/medical care is vital. Look for credentials.
Ensure indoor and outdoor play areas are clean, well-maintained, and designed for safety and stimulation
Webcams allow you to view your dog during the day for reassurance. Make sure they're accessible.
Good daycares have qualified trainers on staff providing basic obedience training and enrichment.
Ask how dogs are grouped by age, size, energy level, and temperament to prevent problems.
The facility should be thoroughly cleaned and sanitized daily. Ask about processes.