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.
But dogs that have blood glucose levels persistently greater than 200mg/dL have diabetes. With the medicines of today, there is no way you can duplicate the normal situation with injected insulin. The best you can hope for is to keep your pet's blood sugar level between 100mg/dL and 150mg/dL. Occasional owners can attain that, but most will find that their dogs peak (spike) considerably higher. Larger or more frequent doses of insulin will drive down these glucose spikes.