“Clean as a hound’s tooth.”
Just a saying, unfortunately.
For an otherwise healthy woman to have an immune system particularly susceptible to a common canine germ transmitted through a lick is, I hope, extremely rare.
Things like this do happen. I saw an episode of Dr. G where a healthy man in his 30s did from the same virus that causes cold sores (Herpes Simplex) For some reason he went septic and his body produced no antibodies against it.