says it all really - shes nearly 14 and has been going downhill for the last 6 months or so - just old age stuff like getting slower, not able to manage as long walks etc.
Took her to the vets about a month ago as her coat had become really think and matted, almost like she wasn't shedding any of her fur - reminded me of a horse with Cushings disease. Vet scanned her and she has an enlarged liver 
the last few days she has been like my shadow - following me everywhere, even to the point of trying to get up stairs after me - up till now she has hated being shut in to the point of chewing her way through doors to get out again. She's also drinking a hell of a lot.
Shes now lying at my feet and her breathing is sounding laboured, but if you speak to her she seems fine and her breathing quietens.
Its breaking my heart - shes been such a part of my life for the last 13 years - been with me though thick and thin, marriage, kids, problems on the farm - shes been my sounding board, my comfort and the one who has always been there with no demands......
Sorry for the long post - just needed to write it down - I'm dreading having to make the "decision"