m terribly sorry to hear about your dog, and offer my sincere condolences. When I was your age, I lost my best friend of 10 years as well,
Rebel. He had developed thyroid cancer on his lower spin, and lost the function of his back legs. They diagnosed him in November, about mid way, and by December (Within a week his health went absolutely downhill) we decided it would just be too cruel to let it continue.
I still remember that day, and its been 6 years now.