Others have already said it but I'll add my condolences also. My Jack was 15 when she passed in March. She was diagnosed with a bad heart valve about 2 years ago and over the last year or so I had to give her several meds. She was always ready to go and meet the next challenge or adventure, even when she was starting to show signs of feeling the pain of old age and the lack of energy that comes with the bad heart. Whenever I went to hook up the trailer so I could load the tractor for a trip to the weekend place in the woods she knew what was happening and got really excited we were going. I always let her run loose in the woods and if I was on the tractor I knew she was there following along. Sometimes it was kind of a pain because I had to watch out for her if I stopped and changed directions but we worked together and never really had an issue. I tried putting her on a long lead and staking her to keep her out of the way but that drove her crazy because she couldn't be there "helping" me. Then when I was doing something that occupied my attention like when I was building my camphouse, she would go off exploring in the woods for about 30 minutes to an hour. She would come back to "check in", take a short break with me and she was off again. But all I had to do was call and here she came back immediately.
I was on the tractor last fall, driving down a trail and I looked back to make sure she was there. I saw that she was struggling to keep up but she wouldn't give up. I slowed down so she didn't have to work so hard. From then on she didn't get to follow anymore, I didn't want to stress her too bad. In her younger days, she would always have her tail pointed straight to the sky and I knew she was happy but starting in January, I noticed she was going around most times with her tail pointed down so I knew she was feeling poorly. She was also getting pretty deaf and was loosing some of her vision due to cloudiness in her eyes. I really started dreading the coming day I'd have to make the decision to have her put down. One fine spring afternoon in March I went out into the garage to do some tinkering and like always let her run the block. Everyone knew her and looked forward to her visits. She used the street pavement to navigate and knew she shouldn't cross the road. On that last day, I heard her squeak and went looking for her. I couldn't locate her. I got in the truck and started driving around looking for her making larger and larger circles. Panic started setting in. I finally went to another neighborhood and giving a description, asked some people who were outside if they had seen her. Yes, they said she ran by recently and gave the direction. I found her on the side of the road breathing her last but trying to get up. I gently picked her up and put her on the floorboard. She started struggling to try and get up so I told her to lay down and I think (I hope so anyway) she recognised my voice and she realized we were back together. I made it home, put a towel on the floor in the garage watched her struggle to breathe but knew it was over. Her gasping for breath got weaker and weaker till she passed. I buried her next to the garage where I usually work so we could continue to be together.
I think what happened is one of the neighbors had company and the stranger, not knowing her, aggressively chased her off (that's why I heard her squeak). That confused her and since she couldn't see well, she took a wrong turn at the pavement intersection and ran herself out trying to find her way home. Looking back, I should have realized she was getting blind and needed the protection of being on a lead but she enjoyed exploring too much.
Sorry for the long rant.
Randall, I still water up sometimes when I drive the tractor (like I am right now as I type this) but just remember like I do; your friend is still there with you and always will be.