Hi! This is truly a WWYD question, because I'm really at a loss, and pretty heartbroken. I thought if I typed it out, it might help me see things more clearly. This will be long (to provide details to try to avoid assumptions, etc.), so I'll try to divide it up.
Backstory
We've had our cocker spaniel (pure bred) since he was 8 weeks old -- he's 6 now (neutered since 6 months old). Our other cocker (also pure bred, neutered at 9 months) was 13 years old when we got the new puppy, but adjusted really well to the interloper. I won't use names, to keep it objective.
Our older one died in 2007, and our new one handled it very well and enjoys being the center of our world. We've noticed from early on that he has vision problems. Doesn't affect his activities, etc. but we have to be careful not to startle him.
Kennelling
We've kennelled both dogs on and off for weekends here and there, and the occasional week-long vacation -- always the same (accredited) kennel. He never has shown any anxiety to go for a car ride, or to arrive at the kennel. This past weekend, he was kennelled from Thursday until my DH picked him up on Sunday afternoon -- I was taking the kids to camp in NY State.
Since he's been home, he's been very anxious about being in the backyard, and has even dug under the fence, which he has never done. DH filled the hole Monday evening and didn't think anything more about it. We have a call in to the kennel to see if anything happened during the stay, but I'm sure they'll say no when they call back.
Biting
About 2 years ago, he started growling at my DD10 whenever she'd come close to him without warning. A couple of times, he would follow up with a nip; once drew blood. Two months ago, DD had a friend over (who has two large dogs -- a lab and a Rottweiler, I believe -- so she has no fear of dogs), and our dog nipped her (no blood). We've just started keeping the dog away from guests as a precaution.
Last Night
Last night, DH took the dog outside (it was a glorious evening) and put him in the backyard. We went to dinner in separate cars, as he had errands to do. When I drove home, our next door neighbor and our neighbor across the street were in our front yard rounding up our dog, who had apparently dug under the gate again and had gotten loose. Our dog knows our neighbor very well.
As she was taking the dog (by the choke chain) back to the yard, I greeted him; he was happy. I picked him up (he's used to it), and he just went crazy. He bit me on my right hand several times, then on my chest, leaving deep cuts and bruises. I kept holding him until he calmed down (I didn't want to risk letting him loose again), and he relaxed again. Neighbor then petted his head, and he bit her hand, hard. She wound up with three stitches.
Advice Needed
So now what? WWYD? Was this a situational problem that might never happen again? Should we put him down? If so, do DH and I do it now, or after we bring the kids home from camp (they're gone until the end of July)? We've already decided not to leave him in the backyard again, but what if he gets loose? I feel guilt either way.
I have had dogs my entire life. I always said that I would never, ever have a dog that I couldn't trust not to bite (the kids know this as well), and we consider ourselves responsible pet owners. We were working around the problem thinking he just didn't have patience with kids. Our neighbor is very well known to him, and for him to bite her, and me, it's just really disconcerting. And sad.
Thanks for reading and for your help.