Symptoms:

Hypoglycemia, the medical term for low blood sugar is a condition in which there is a drastic, sudden dropping in the level of blood sugar in the puppy.  It is a puppy disease most often in seen in toy breed puppies and usually not seen in puppies over twelve weeks of age.  It is most likely caused by the uneven spurts in growth of the internal organs of the puppy, especially the pancreas.  The brain will receive incorrect signals from the pancreas and not send out a correct signal for the release of a proper amount of sugar in the bloodstream.  Signs of an attack are a weakness, confusion, wobbly gait, frothing or drooling from the mouth - sometimes even a seizure and drain of blood from the head.  A check of the gums will show them to be pale, almost a grayish white in color rather than a healthy bright pink.  The puppy can go into shock and, if not cared for properly and promptly, may even die.

Causes:

Hypoglycemia can be an inherited condition.  If a female has been hypoglycemic, it's likely that she will pass it on to her puppies.  For the young pup prone to this condition, even a brief period of fasting in a toy breed puppy can trigger a hypoglycemic "attack", Any significant stress, such as a routine trip to the vet's, that occurs in the absence of a recent meal, can cause the blood sugar to drop to dangerously low levels.  Low environmental temperatures, infections, vaccinations, strenuous exercise, and inadequate nutrition increase the risk even further.

Treatment:

Feeding recommendations for puppies at risk for hypoglycemia include: frequent (4-5 times a day) feedings of high-carbohydrate, high -protein and/or -fat foods.  Feeding soft moist foods may help to prevent a hypoglycemia attack due to the high sugar content.  Gatorade mixed with a little honey, Ringers lactate with dextrose or Pedialyte are good products to use if dog is having an attack.  These products have electrolytes, which ailing puppies need.  Honey and corn syrup can be used also.  For pups that have had recurrent or prolonged signs, monitoring the urine for ketones with a "dipstick" made for diabetics is helpful, since a return to "ketone negative status" signals a return to normalcy.  If these measures don't correct the problem, a trip to the vet is recommended.  Intravenous feedings may be necessary and the vet will need to check the puppy for more serious problems.