Dogs with dental infections may have stubbornly high blood glucose levels. Since it's not always obvious that a tooth is infected, it's possible for this infection to be hidden, and appear only as a mysterious regulation problem. 
Illness places the body under stress, which can raise blood glucose levels. It also goes to work trying to rid itself of the problem; this causes some hormonal release of some of the same counter-regulatory hormones the body releases when it feels it's being threatened with hypoglycemia.  This can make it difficult to keep in good control using the same amount of insulin when there's no illness. Humans with diabetes have "sick day" plans; on those days, more insulin, more blood glucose testing and checking for ketones may be needed.
Ask your vet about dental procedures. Warning: Many vets will refuse to perform a dental procedure on an unregulated diabetic, even if the infection is what's causing the lack of regulation. Yet another vicious circle in diabetes.
List of Board-Certified Veterinary DentistsEdit
- Diabetes and Periodontal Infection: Making the Connection Southerland, Janet H., et. al., 2005, Clinical Diabetes
Although this is a human-based article, it gives a fine overview of the special dental problems of diabetes.
- Management of multiple dental infections in a dog with diabetes mellitus Van Nice E., 2006, Journal of Veterinary Dentistry
- Periodontal disease Niemiec BA., 2008, Top Companion Animal Medicine
- Home Care for Prevension of Periodontal Disease in Dogs and Cats-Page 4 Hale, Frasier, 2006, Hill's NAVC/WVC Symposiums