Dog attack!

[SunnyLan]

I have always heard that if a dog ever gets a taste of chicken blood it's over. Will I ever be able to let my chickens out again?

First of all, sorry for your loss, I have silkies myself
Second, regarding your dogs. Duchshunds, unfortunately, have a very strong prey drive as they were bred for hunting. Because they are rather small breed, people tend to treat them liniently. But obedience training is a must for a dog of any size! Not only for your safety and confort, but for safety of the dogs too. You need to teach your dogs to recall. You may want to aquire an e-collar (yes, they should be used ethically).