Winston is adorable. I'm sorry he is struggling with diabetes. As Wylie's Mom indicated, Maui Girl has experience with canine diabetes.
My brother's cocker spaniel was diagnosed with it this year. She is being regulated with insulin and eats a prescription canned food from the vet.
I am concerned that the diet you are feeding is not nutritionally balanced. Also, maybe Winston is not getting enough food? When I feed my dogs fresh food, I'm not sure of the amount to give them. A consult with vet nutritionist might be a good idea. This is likely not the whole answer to Winston's problems, but could help.
Sending best wishes for your little boy.
__________________ Kristin, Max and Teddy |