It's unusual for a dog adult dog over 5 pounds to have hypoglycemia, as the common cause is just not having enough fat or energy reserves like we would see in puppies. An adult dog does require further investigation. Here’s what one site says about some of the causes.
Quote:
COMPLICATING FACTORS
Sometimes there is more to hypoglycemia than just low blood sugar. While being extra small and extra young is enough to drop one’s blood sugar, sometimes there is more to the story.
Bacterial infection Bacteria can be tremendous consumers of glucose (blood sugar). For this reason, hypoglycemic puppies frequently are given antibiotics.
Portosystemic (Liver) shunt This is a problem for the Yorkshire terrier in particular. In this congenital malformation of the liver circulation, blood travels from the GI tract to the general circulation by-passing the liver. The liver does not develop properly and has abnormal function. One of the liver’s functions is to maintain the body’s blood sugar level. An abnormal liver leads to low blood sugar. This condition can frequently be cured with surgery. A liver function blood test is an easy way to rule this condition out as a complicating factor.
Parasitism/Diarrhea/Stress Stress from any cause increases the body’s demand for sugar. This is why it is especially important to insure the general health of the toy breed puppy. When stressors are present, maintaining a healthy blood sugar level is all the more difficult.
When your puppy comes home again after a hypoglycemic episode, it is important to watch food intake and be aware of any changes in energy level. As the puppy gets bigger, risk factors diminish. Teeth get stronger, body fat stores develop, and the immune system matures. Eventually, hypoglycemia risks become minimal and the puppy can continue life as any other puppy, playing, chewing things up, and learning the behavior control necessary to be a good house pet.Toy Breed Hypoglycemia |
This site has a few more causes:
Quote:
A common cause of hypoglycemia in dogs is a functional islet cell tumor of the pancreas (insulinoma). While a wide variety of breeds may be affected, Labrador Retriever, German Shepherds, Irish Setters, Standard Poodles, Collies, Boxers, Fox Terriers, and most Toy breeds may have a higher incidence than other breeds. Insulinomas occur less frequently in cats.
Hypoglycemia can result from excessive insulin administration to animals with diabetes mellitus, and cats may be at greater risk of insulin overdose than dogs, especially if the cats are obese and receiving insulin doses > 6 U/injection, administered once or twice daily.
3. Hypoglycemia in highly nervous hunting dogs is also well recognized. Attacks are characterized by apparent disorientation, weakness and generalized seizures. Recovery is rapid; however the affected animal's hunting ability is compromised. Frequent feedings with protein-rich foods and/or candy bars may prevent the attacks. The cause has not been determined.
In adult dogs, hypoglycemia may also occur with severe Addison's Disease (failure of the adrenal gland to produce the necessary hormones), liver disease (e.g., impaired glucose production and glycogen storage), sepsis, and as a complication of pregnancy accompanied by ketonuria (the presence of ketones in the urine, a dangerous feature of severe and uncontrolled diabetes). Hypoglycemia Symptoms and Treatment |
So there are quite a few causes in adult dogs and you are wise to have your vet look further into the cause. I hope your vet can find out what Callie's problem is and hope it's nothing serious, many of these things can now be treated fairly easily. You're a good mom for noticing the gums, so many people would have ignored it.