I hear the "zoo" /zu/ in "zoology" (/zuːˈɒlədʒi/, /zuˈɑlədʒi/) almost universally now. I think I’m the only one left saying /zo/ in "zo-ology" (/zoˈɑlədʒi/, /zoʊˈɑlədʒi/, /zəʊˈɒlədʒi/). Am I alone?
I used to say zoo-ology until I came across words like zoological and zoogeography. That's when I actually looked up the pronunciation of those words, and in the process found out that zoology is pronounced zoe-ology, at least traditionally.
The American Heritage Dictionary has an interesting usage note on this:
Traditionally, the first syllable of zoology has been pronounced as (zō), rhyming with toe. However, most likely due to the familiarity of the word zoo (which is merely a shortened form of zoological garden), the pronunciation of the first syllable as (zo͞o) is also commonly heard. In 1999, 88 percent of the Panelists found the (zō-) pronunciation acceptable, and 60 percent found the (zo͞o-) pronunciation acceptable, with 68 percent using the (zō-) pronunciation and 32 percent using the (zo͞o-) pronunciation in their own speech. Thus, while both pronunciations can be considered acceptable, the (zō-) pronunciation may be perceived as more scientific.
American Heritage Dictionary
Note the AHD uses /ō/ for the vowel sound in "toe", and /o͞o/ for the vowel sound in "too", while other dictionaries can use /oʊ/ and /u/ respectively. Collins and Oxford use /əʊ/ for what might otherwise be transcribed as /ō/ or /oʊ/. In other words they all represent the diphthong in "toe" or "tow".
So in 1999 32% of the dictionary's Usage Panel used initial /zu/, as in the "zoo" where animals are kept. That's quite a high number in my opinion for a dictionary usage panel, which are sometimes known for their conservative views. I would imagine (though I don't know for sure) that the percentage of people among the general population pronounce it with initial /zu/, though that's just a guess.
It's interesting, because BrE dictionaries that give both pronunciations give the /zuːˈɒlədʒi/ pronunciation first, and the /zəʊːˈɒlədʒɪ/ pronunciation second. In AmE dictionaries the initial syllable of /zoʊ/ is given first, and some don't even list the variant beginning with /zu/.
For example, Random House Unabridged shows only
and Random House Kernerman Webster's College Dictionary shows only
(zoʊˈɒl ə dʒi)
Furthermore in Cambridge Dictionary the pronunciation for UK English is given as /zu/-ology while the American pronunciation is given as /zoʊ/-ology. Longman Dictionary of Contemporary English seems to show the same thing with respect to British and American pronunciation.
So from this I gather the /zoʊ/-ology pronunciation is more common in AmE, though I can't be sure.
Some other people say "zo-ology"
You aren't literally the only person left who pronounces the first syllable of "zoology' with the vowel found in goat rather than the vowel found in goose.
A useful resource for finding data about how people pronounce certain words is Youglish, which you can use to find Youtube videos where the word in question is spoken aloud. If you go through the Youglish results for "zoology", it doesn't take that long before you hear the pronunciation with the goat vowel. I listened to the first 24 or so pronunciations and heard it pronounced with the goat vowel more than once.
The "zoo-ology" pronunciation seems to have been in use for quite a while
A note on the concept of "traditional" pronunciations. The use of the goat vowel in "zoological" words follows the usual rules for the pronunciation of English words derived from Latin or Greek, while the use of the goose vowel violates these rules, but this doesn't guarantee that the pronunciation with the goose vowel is particularly recent. The "traditional" rules took time to develop and to be enforced, and even in their heyday they weren't universally followed.
In a comment beneath the question History of pronunciation of “moiety”, ruakh pointed out that we see strong evidence of the pronunciation with the goose vowel being used in a humorous poem from 1829, "The Progress of Zoology", which rhymes the zo- of zoological with hue, view, emu, u-(niverse), su-(perfluous), and too. You can see the poem via Google Books in this text from 1892.
To be clear, there is good evidence that the pronunciation with the goat vowel is not recent either; John Walker's Critical Pronouncing Dictionary of 1791—which despite containing strong prescriptivist elements was partly descriptive—only gives a pronunciation with the goat vowel. It seems likely that both pronunciations have coexisted since more than a century ago.