However, in most instances, a difference of a few days is unlikely to have a negative effect on immune response. With the exception of rabies vaccine, ACIP allows a grace period of 4 days (i.e., vaccine doses administered up to 4 days before the recommended minimum interval or age can be counted as valid).
Blood Glucose in Dogs. Healthy dogs have normal blood glucose levels, which tend to range from 75 to 120 milligrams per deciliter of blood. Dogs that have levels of 80 milligrams per deciliter or lower are likely to develop hypoglycemia.
Milk contains a lot of lactose and in order to absorb the lactose the dog's body must be able to produce lactose-splitting enzyme known as lactase. In general, most of the dogs have very poor levels of tolerance to lactose and lack necessary enzymes (lactase) to break this component so that they can absorb easily. As we say prevention is better than cure, it is better for you not to give milk for your Lab. If you still want to give milk to your pup.