Some of this is not a training problem, and treating it like one wastes time your dog may not have. If they are distressed when you leave, if they growl or guard their food, their toys or you, if they are frightened on the lead, or if anything about them changes suddenly at any age, contact your vet the same day. A tip from a website, ours included, is not the answer. If it cannot wait, contact your nearest emergency vet now.
With a Shiba, the hard part is telling protest from pain. A scream when you pick them up the way you always do, a new sore spot, or a Shiba who stops grooming themselves is telling you something. So is paw licking that goes on for hours, or skipping on a back leg. In an older Shiba, slowing down and gaining weight can be an underactive thyroid, and pacing at night can be the start of cognitive decline. Bloat (GDV, a twisted stomach) can happen in any dog, though it is most common in large, deep-chested breeds. A swollen, tight belly, retching with nothing coming up, sudden restlessness or drooling is an emergency: contact your vet now. It is easy to put the rest down to attitude, and that can cost months.
They'll keep holding out for chicken. If they stop coming for it, tell your vet.