Hi Jodi,
Nice to see you checking out the other questions on the forum. I'm sure you can offer some advice. Regarding using a Yang tonic, I see your point. The only concern would be that autoimmune conditions are generally pathogen invasions. As you know, they must be given an outlet. Otherwise any tonic that is used could tonify the pathogen as much as the patient and re-awaken a latent autoimmune tendency.
Keeping that in mind, one option for this dog of Michelle's might be to pair Xiao Chai Hu Tang (Minor Bupleurum) with Si Wu Tang (Four Materials Decoction). This makes Chai Hu Si Wu Tang. The former tonifies the Source Qi through Ginseng and introduces a Yang element in the form of Bupleurum. XCHT as a whole helps carve a path from the interior to the exterior, along which the pathogen can be evacuated. Si Wu Tang tonifies the Blood.
So this is another option. The pulse and tongue are not inconsistent with Qing Ying Tang, however. QYT deals with Blood Heat, which causes desiccation and dehydration. Hence the many Yin tonics in the formula.
As for the pulse and tongue, they can vary. The pulse for Qing Ying Tang frequently feels deep and wiry. The tongue can be dry, as stated, but may be lavender, dark red, brick red, or even pale if Blood has really become damaged and deficient.
So hopefully Michelle will be able to choose from these. To avoid aggravating any coldness, then starting slow and low with the Qing Ying Tang would make a lot of sense. But given the restlessness of the animal, I wondered if the slow pulse was 'constitutional' or normal for the dog.
Steve