Have you or your vet ever done a glucose curve to chart Winston's fluctuations in blood glucose throughout the day? We do it with our diabetic dogs, but it might be helpful in Winston's case.
Here is some information:
Blood Glucose Curves in the Diagnosis & Regulation of Diabetes in Dogs BD Diabetes - Learning Center - Caring for a Pet with Diabetes - Diabetes in Dogs - Monitoring Your Dog - Blood Glucose Curves
You can make your own curve in Excel:
Pet Diabetes - Anne's Excel Instructions for Canine Blood Glucose Curve
Blood glucose normally drops during a seizure, so perhaps hypoglycemia isn't the cause, but rather the effect of the seizure?
Have you discussed putting Winston on an anti-seizure medication? If he keeps having seizures for whatever reason, they will become more frequent because of a phenomenon called "kindling".
Kindling is the experimental phenomenon whereby repeated stimulation of the brain can eventually induce a chronic epileptic state that persists after the stimulation is stopped.
The underlying mechanisms of kindling are incompletely understood but involve changes in the electrical behavior of a group of brain cells. This may be related to alterations of chemical receptors (specifically what are called NMDA subtype of glutamate receptors) and changes in how these brain cells connect with each other through structures called synapses.
In a sense, by having repeated seizure the brain "learns" how to have seizures. Think about how a young child learning to write their name has to concentrate when printing each letter. After doing this over and over, we become able to quickly write our name without even thinking about the intricate hand movements involved. Obviously there is some change in our brain that allows this to happen, but it does not have to be a structural lesion.
I think of kindling as something similar. The brain is doing what it is designed to do...learn. It is just learning to do something harmful like have a seizure.
WB Thomas, DVM
Dipl. ACVIM (Neurology)
University of Tennessee
Knoxville, TN
Canine Epilepsy-Frequently asked questions about the diagnosis, treatment and management of seizures in dogs