If your dog is given too much insulin, it can result in low blood glucose, which can cause disorientation, weakness and seizures. If your diabetic dog develops any of these symptoms, give him food right away.
If he is unconscious and can’t receive food, rub corn syrup on his gums, then feed him when he gains consciousness. If you aren’t able to remedy the situation, seek veterinary help immediately.
Sources
ASPCA. “Diabetes.” (May 28, 2011)
http://www.aspca.org/pet-care/dog-care/dog-care-diabetes.aspx
Cohn, Leah. “Diabetes in Dogs.” PetPlace. (May 28, 2011)
http://www.petplace.com/dogs/diabetes-in-dogs/page1.aspx
Fleming, JM; Creevy, KE; and Promislow, DEL. “Mortality in North American Dogs from 1984 to 2004: An Investigation into Age-, Size-, and Breed-Related Causes of Death.” Journal of Veterinary Internal Medicine. Feb. 25, 2011. (May 28, 2011)
http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2011.0695.x/full
Healthy Pet. “Wellness Exams.” (May 28, 2011)
http://www.healthypet.com/petcare/PetCareArticle.aspx?art_key=45a3d71d-734b-4507-94db-22eb4aa47cd6
Healthy Pets, WebMD. “Dog Diabetes Symptoms, Treatments and Diet.” 2007. (May 28, 2011)
http://pets.webmd.com/dogs/diabetes-dogs-symptoms-treatments-dietary-management
Nash, Holly. “Diabetes Mellitus in Dogs.” Pet Education, Doctors Foster and Smith. (May 28, 2011)
http://www.peteducation.com/article.cfm?c=2+2097&aid=3587
UPI. “Diabetes in dogs and cats on the rise.” April 22, 2011. (May 28, 2011)
http://www.upi.com/Top_News/US/2011/04/22/Diabetes-in-dogs-and-cats-on-the-rise/UPI-40561303506067/