Ibaker -- you don't tell us what breed the "momma's boy" is, nor how old, nor, exactly, how you lift him, but I'm with LizBud -- a trip to the vet is definately in order. It sounds like some sort of pain response. Could he have dysplagia? Even small breeds can have this. Perhaps a muscle pull? I would go check this out.

Ilovebrits -- I believe I would spend some time giving her some of the goodies and making her give them back. Yes, they are treasures to her, but you are still the "giver of the goodies" and she should learn that as long as she is well=behaved, she'll receive it back. "Take" and "give" are the commands I would use here. If she doesn't want to "give", I'd say no more and into the crate for time-out. Protective behavior is not unusual, but she needs to know that she can trust you and that you "stand over" her in the pack. Practice this every time you give her one of these treats until she can be "trusted" to behave and then, occasionally, after. She needs to know that whenever you want the treat, she must give it. Good luck and let us know how it goes.