Amazing, isn't it, how many (expletive deleted) rude people there are out there. I mean, maybe she was stressed out about the dog's condition and/or worried that he might bite, but there's more polite ways of communicating that.

I'm reminded of an incident that happened at my store during the Christmas season. When the checkout lanes get too backed up, all employees are expected to jump on a lane and help out, and this includes upper-level management as well. We all wear the same uniform, basically, so you can't tell what level the employees are just by appearance. So our store manager, a very nice young lady, was checking people out, and making small talk with a nicely dressed woman who was buying some mens sweaters. The lady mentioned that they were for her son at the University of Minnesota, and our manager said hey, I graduated from U of M too, it's a great school! The transaction was wrapping up at that point, and this lady looked at her with a really condescending expression, and said "and look what you're doing now......", took her package, and walked off without a goodbye, Merry Christmas, anything.
That's the thanks we got for making sure she got through the checkout lines in a hurry. Our manager was spitting nails about that for a while!