Some basic advice on making and using bug out bags for your dogs and cats
http://urbansurvivalsite.com/bug-out-bags-dogs-cats/If your dog is large enough, they carry their own bag. Cats... not so much - you are their servant, not the other way around.
A dog can be trained to carry at just about any age, but starting early will make it easier. Once they learn that they are carrying their own food, they will usually understand and cooperate.