Out of the blue our dog had started acting weird. She would go stand in a corner and not remember how to back up and get stuck there and we would have to help turn her around and then would walk around a room over and over and then go in another room and do the same thing. The vet suspected a brain tumor but we did not want to send her to a specialist and put her through all of the testing to confirm since with her being so old they would not do much of anything anyway to treat it. She kept going downhill and we knew it was time. Within a few weeks after she was gone we went to the same shelter and found our current dog. I know everyone is different but it really helped us cope with the loss knowing we were giving joy to another dog.