great video
worth adding my own girl who bloated didnt froth at all, however we perhaps caught her abig early .... my rule is if they dont look well, measure there stomach area, wait 3 mins and remeasure.... if they grow then straight to vets.
i have had the odd "funny look" from a dog, ive paniked and measured and been reassured they are fine after a couple of measurements a few mins later .... well worth knowing where your tape measure is!