Jon B Wrote:
-------------------------------------------------------
>
> A friend of his went to Vietnam and as dog is
> served in some Restaurants he had some. Now,
> apparently, whenever he walks past a dog in
> Thailand it growls as it knows what he did.
>
This might not be all that farfetched a belief.

If, because of his dinner selection, Thew's friend feels guilty or somehow tainted or fearful now whenever he meets a dog this will be very apparent to the dog. Dogs are expert at reading humans not only through sight cues but also through hearing and through a very acute sense of smell.

Three years ago there was a good article in the Washington Post about just how good dogs are at reading humans. Here is an excerpt:

[...] a study being published simultaneously today helps explain what may be the most enduring canine mystery of all: What is it about dogs that makes them so compatible with people? In the first direct comparison of its kind between dogs and chimpanzees, dogs demonstrated an uncanny ability to interpret human communicative cues -- gleaning information from subtle hand gestures and even getting the meaning of a human glance -- while the brainy chimps remained clueless to what was going on.

It may not be news to dog owners, but now it can be said with some scientific assurance: Centuries of selective breeding has created an animal that in some respects, at least, understands us even better than our closest primate cousins.

"It looks like there's been direct selection for dogs with the ability to read social cues in humans," said Brian Hare, a Harvard biological anthropologist who led the behavior study.
From [www.washingtonpost.com]

t.