Preferred Dog for TEOTWAWKI

I raised Collies for over 20 years,tried Shetland Sheep Dogs and,for the last 13 years,Ive been a German Shepherd Person.

I only use West or East German or Czech Working lines for health and temperment reasons.

My dogs are an integral part of my family security/defense planning.

Just wondering what breeds others prefer and why, also do you plan for your dogs to "earn their keep"?

Preferred Dog for TEOTWAWKI