I had a Yorkie/Poodle mix that was diagnosed with diabetes at age 8, I was very lucky to have a vet who was very educated concerning canine diabetes. He was put on th science diet WD, and i successfully gave him two insilun shots a day for the next five yrs, until he passed away at age 13. He did very well, and had near normal life after diagnosis. Unfortunatly he did go blind about 1 yr before he passed away, but he was still a trooper, and a happy little guy.
If a dogs owner is willing to go to the expense, and time, to take care of their dog, then the vet should be willing to explain to you the details about how to go about it. Of course my dog did not have juvenile diabetes, so I have no idea if that is a different situation or not.
Your vet should be able to explain to you what the options, and treatments are, and then let the decision be yours. If he/she does not do that then i would be finding a vet who will!
I wish you the best for your little baby!
