OK, let's *for the moment* "presume" this is in relation to a "real world" situation. Thus, let's "apply" it to the one in which you and I are presently functioning: alt.dreams *in* Google Groups, which is *ending* in (approximately) 3 days.
I *just now* switched over to *this* system (a relatively new Acer Chromebook) from my parents' *rather older* XP system (with Outlook Express.)
I was investigating "how to" set Usenet *back up* on Outlook Express. Apparently, it *requires* a *valid* email configured *in the OE app* (as it were) in order to *send* the replies (or new "posts") *to* the news server (the USENET portal.)
I'm starting with:
news.eternal-september.org -- now, I *just now* realized that *that* address can be entered into a web browser page *as is* and *that* takes you to a registration page. (I'd been doing this through OE and *NOT* via any registration page. That *may* explain why I can't find alt.dreams ... yet.)
At any rate, IF you have YET to start trying to get up a Usenet "news reader" *other* than Google groups, then I *strongly* suggest you start looking.
How this relates to your dream:
Well, a black and white cow refers to *many* types of cows, both beef *and* dairy (but a dairy cow, typically.) (
https://petkeen.com/black-and-white-cow-breeds )
However, applying it to *this particular situation* (the Google groups / Usenet issue) the cow *was* "drinking with it's front feet in the canal" --
1) the "black and white" reference refers to the (normal) screen viewed while using alt.dreams: white background, black text, or when reverse, black background, white text (old school CRT style.)
2) the *water* refers to the "stream of information" that Usenet provides (from the "river" of the internet, from the "ocean" of cyberspace.)
3) that the cow was using "it's front feet" (or "hooves") in the water refers to how the user (in this case, analogous to yourself, as all cows are female) analogously uses one's front hands to type to/from Usenet (the stream of information.)
Seriously, tho, *if* you wish to continue using USENET for information exchange (as it may soon become about the *only* way of easily transferring digital information, and even then, likely to become censored, such as how Google is dropping its access to Usenet in order to curtail / censor / obliterate free speech) *then* it is very advisable to start looking *now, today* for ways to "make it work."
(Also, as a last gasp, at least for the time being, there's "Truth Social" and also that other system that got shut down temporarily almost the moment it was about to "go big" as vehicle of free speech.... "Parler" ... however, I'm simply trying to keep the years-long record of posting to alt.dreams "going for the record," as it were.