That's what I thought at first, being a big animal lover, but it's similar to grabbing them by "the scruff" of the neck, which like Dirk said nursing mothers will do with kittens.
Though I dislike the practice and have never picked my cats up that way, those that I've had over the years, I can understand the necessity for the vets to do it.
It's similar to "tonic immobility" in most sharks and also I've seen it done with alligators, where they turn them upside down and stroke their bellies inducing a type of torpor. No harm is done to the animals.
This is the vid the gif came from.
http://youtu.be/KT5YfJNuJAY
Anyway, enough seriousness. Lets get back to the threads theme.