We had to put our 1st sheltie down after she got cancer. We made the decision after my, then 3 yr. old daughter, went to let the dog in & she didn't come in. It was awful. We'd had her about 7 yrs. Another pup from the same litter also had cancer. We got a 2nd sheltie several months later. He would have strokes, walk like he was drunk & then come out of it. He didn't come out of the last one. We also put him down. That was on a Wednesday. The following Saturday, I came home with a 4 wk. old puppy. We found out the following Wednesday that she had parvo. She had a 50/50 chance of making it. I couldn't put down 2 dogs in 1 week. Just couldn't do it. She made it. 2 1/2 yrs. later she is the biggest baby ever. She's my baby. It's going to be very hard when the time comes and we all know that with pets the time will come.