Update on Archie:
He had an EKG yesterday afternoon due to the concern for heart damage. The EKG came back normal, which is obviously huge.
Overall, he's improving. Still in Critical Care on oxygen, feeding tube, monitor, etc...but we're fine with baby steps.
When we saw him for our PM visit yesterday, he really wagged his tail for the first time... which may not mean anything clinically, but meant the world to us. He's fighting and he's determined to come home.
I also wanted to add that one of the other affected dogs did go home from the vet earlier this week. She still has some rest and healing to do, but we're so happy for her and her owners.