I had a pair of Rotties that were inseparable, actually mother and son. Roxie my female got congestive heart failure and at age 13, I knew she was suffering and I decided to ease her pain. I was VERY worried about Moose, her son, he was so attached to her he was 6 years old when Roxie died. We had the vet come to the house and put Roxie down at home. I allowed Moose to sniff Roxie and he was with us when we buried her. His attachment to her seemed to quickly transfer to me and it was a huge problem. If I left home for anything I could not leave him loose in the back yard (he would tear down a section of privacy fence and would wait by the garage for me to get home) this actually happened on more than one occasion, and if I left him in the house , he had to be in a crate or he became destructive in the house but he howled and cried constantly. (these were all behaviors that he never had while Roxie was still alive. His separation anxiety was extreme and my vet suggested I put him on medication. I didn't want to do that so about 6 months after loosing Roxie I brought home Zoe a 12 week old puppy and Moose was transformed. He loved Zoe and they became the best of buddies. I lost Moose at the ripe old age of 14 and he loved Zoe to the very end. I became involved in Schutzhund and had added a Belgian Mal to my household so Zoe had Allie when I lost Moose. I don't know if getting another dog is a possibility but it did help my guy.