Very depressing question, esp at this time of year. I previously had a Sheltie with a liver shunt and it was obvious when life was no longer worth living. I currently have a almost 12 yr old Sheltie with advance elbow arthritis and panic attacks. My husband and I are just beginning to discuss this. I was wondering if anyone could share how they knew their Sheltie was no longer enjoying life and was ready? Thank you.