This still hold true today - but most of us have been warned to not stare a guard dog in the eye.. lol
When the creature is irritated, the pupil invariably dilates, and by singly marking this circumstance, the temper of the beast may be correctly ascertained.
The article excerpt from the book was written in 1854 when things were a lot different. Dogs were not largely judged on beauty and conformance to a certain look but rather on their behavior. The were considered beasts with a purpose and so were valued for their utility be it guarding, retrieving, killing rats, hunting deer, wolves, or little furry critters in the underbrush. So if we look at the time frame this was written and the experience of the author up to that point from 1813-1854 was can see that as a time of difficulties and pioneering to west. Most farmed or raised livestock and basically lived off the land so it was paramount that their assets "wealth" be protected.
When I read old articles like this I try to envision the time when it was written and the disposition and lifestyle of the people who wrote them. Because I read a lot of history books and read novels of past time I do have a fairly good grasp of "those times" and the hardships faced.
Enough of my ranting now.. You have done fantastic work with your dogs and the situation at the vet that you described is admirable. That takes a lot of work, experience, and dedication to your dogs. Unfortunately most dog owners today do not take the time to invest in training their dog the way you do. Great job.
I am not sure what breed the dog that was handed off to the vet was - so here is the question to continue the discussion: Do you think that any of the guardian breeds (e.g. Central Asian, Caucasian, Black Russian, South Russian, Great Pyrenees, Kangal, Sarplaninac) could be so trained as to be totally trusting of the vet's staff?