My large dog was diagnosed with diabetes 2 weeks ago. He gets 2 shots of 15 units each right after he eats at 7a.m. and 7p.m. The vet just raised his shots to 20 units because his blood glucose was still at 25-30 even with the 15 units. Should my dog be getting a snack? Should we wait 2 weeks before raising the insulin? How much is too much of one kind of insulin? Should we be trying a different kind of insulin instaed of raising the caninsulin? Please help. It breaks my heart to see him so sick.