Guardian Dog Woes

We use livestock guardian dogs and llamas to protect our sheep from predators - critters like coyotes, mountain lions and domestic dogs.  We currently have four guard dogs - Buck (our oldest and most reliable dog), Boise, Reno and Vegas (Boise's daughter).  Buck is a reliable guardian for lambing ewes - we call him Uncle Buck, because he lets the lambs climb on him while they're playing.  Buck is getting older (he's 8 or 9), so we're hoping one of the younger dogs will develop into a reliable lambing dog.  Boise shows promise - we're finding we can trust him more and more.  We have high hopes for Vegas, too - she's becoming a great dog.  However, we found out today that at just a year of age, she's not yet trustworthy with newborn lambs.

Lara's oldest ewe, Woolie, gave birth to twins today (a week or so earlier than we expected).  When Sami and Lara discovered that she'd lambed, they found one lamb dead and the other chewed up - by Vegas.  While losses like this are one of the risks of using guard dogs, I struggle with it when it happens.  I love the dogs, but I feel like I've failed the sheep.  I'll agonize over this for the next several days.  We'll work with Vegas to help her understand acceptable guarding behavior.  As she matures, she'll hopefully begin to understand her job better.  In the meantime, we'll use a llama to guard the lambing ewes here at home - llamas aren't as effective with some predators, but they are safer with the new born lambs.