Toys Aren't Sanitized
Although most, if not all, states with agencies regulating daycare cleanliness have seemingly stringent rules about de-germing playthings, who's to say these guidelines are being followed? Sure, inspections take place from time to time, but few daycares sterilize their germ factories (also known as toys) on a daily or even weekly schedule.
This means that by the time your teething toddler gives a spit polish to the plastic dishware that comprises the daycare's toy kitchen, it's already loaded with minutiae left behind from her cohorts. If you've asked about the daycare's toy sanitation policies to no avail, volunteer to spearhead the effort. Your willingness to help will probably prompt them to action. In addition, make sure your child is up to date with immunizations and instill healthy habits at home, such as handwashing.