More condolences from me. Pippin was regarded by us as a distant friend, through YACF, so I feel like we've lost a friend too. We've done the same trip less than a year ago, and the vets brought in tissues into the room where the deed was done, ready for Mrs W and myself. They got used, copiously.
The bit I found hardest of all, coming home, and Baggins refused to have anything to do with me because I'd obviously killed his mate Tirion. God, that hurt. All that love is now concentrated on Baggins, and he is now forbidden from dying, ever....
So, farewell Pippin, you were a lovely cat.