Deliciously plain yogurt is a healthy treat for your dog. Just as with humans, the live acidophilus in the yogurt keeps the good bacteria in your dog's intestines in balance, so that bad bacteria is swiftly knocked out. If your dog is on antibiotics, a little yogurt will also help keep yeast infections at bay (a common side-effect of antibiotic treatment). You can also give your dog acidophilus pills -- wrapping the pills in bacon is strictly optional.
Puppies are especially prone to yeast infections, so a little plain yogurt as a snack (or even dessert) can help keep things in balance; especially useful while the intestinal system is building immunities.
Source