Stress may be more discrete in some people, but you appreciate it in the more rapid speech, the increase in gesture and hand speed, or the rigid clamping of hands to lectern, but it's there if you look. The differences between members of the same species as to what stresses them are probably less than the differences between members of different species. Any of you present at the Chicagoland and BCCA specialty in 1995 who attended the seminars may remember while I was giving a serious talk on Addison's disease the audience started to titter and laugh. Einstein, who was there to demonstrate grooming technique, had decided to stick his furry head through the curtain for a peek at the audience. In this case the curtain was under the lectern at which I stood, so our heads were superimposed.
Stress is certainly transmittable from animal to animal and species to species.
If you are nervous going into the ring, your dog will be too. One thing which struck me on my return to Britain this time was the absence of dogs on the street. Probably this has been a result of the dangerous dog legislation over there. When I took my sister's Pembroke Welsh Corgi, Bea to the shops we only encountered one other dog. Dogs are still allowed in food stores in England, but Bea was definitely in a minority.