i am very sorry to hear this. I went trough this a few years ago. I had to put him down too but het was moeilijker om hem te zien leiden dan om hem in te laten slapen. Natuurlijk doet het zeer maar toe kijken hoe je hond leidt doet veel meer zeer.
I hope you find a new compagnion. It will never be the same but every dog has his own wonderful personality.