Panting and shivering are vague signs that can suggest nervousness, fear, fever, or pain. Did your vet take her temperature at that visit 5 days ago? Even if they did, it probably should be checked again to make sure that she doesn't have a fever.

I suspect your dog is having some discomfort somewhere and it can be challenging to figure out where exactly the problem is. The most common location would be in the neck or spine. These dogs will often yelp if they are picked up or try to jump on the couch. Dogs with neck pain often appear to have difficulty resting comfortably or lowering their head to eat out of the food bowl. Another possibility would be pain in the abdomen because of her recent vomiting problems. She could also be exerpeicing some acid reflux type discomfort because of the recent vomiting. Severe dental disease can also cause significant pain.

Other causes of panting include heart and lung disease. Even though everything sounded fine, some things will show up on an x-ray that cannot be heard by listening with a stethescope. Cushing's disease (adrenal gland problem) can cause panting, but should have had an elevated alkaline phosphatase (this is a routine liver enzyme time) on her previous blood work. Overweight dogs pant more, but wouldn't expect shivering. Metabolic acidosis (a metabolic abnormality) also can cause panting, but should have shown up in her previous blood work.

I would recommend having her seen again by your vet. Make sure they take her temperature and feel her neck and spine for evidence of discomfort. If they can localize her pain, they likey will recommend an x-ray.