Some vets don't know the first two things about Newfs. When I first got Admiral I went to Banfield and all the vets gushed about her condition and good health. I asked about her front legs splaying out, every one of them said she looks fine. Naïvely thinking they knew what they were talking about, I followed their every instruction--including spaying her at seven months. After the spay, as I was picking her up, the vet casually mentioned, "Hey, she has a recessed vulva, must be why she has so many UTI's." So I went home and did research and found all this info on why I should have waited to spay. Needless to say, I was livid.
Thanks to a nearby breeder, and several other members of Colonial Newfs, I found the amazing vet I see now. When we met him and told him we were referred he said, "Let me guess, you guys belong to Colonial Newfs." And when I asked the vet tech how many Newf patients they have she told us, "Hundreds." This made me so happy! On Admiral's first check up with him, he told us that: yes, we spayed too early and we might need to do a vulvaplasty; yes, she has bilateral carpal valgus in her front legs; and yes, she's 10 lbs. overweight. I was so relieved to have a vet tell me what I had been suspecting all this time. When I told him the story about our old vets he said he was not surprised, the science behind waiting to spay is relatively new, and most vets just don't know the needs of giant breeds because they don't bother keeping current on new information.
Long story short, sorry you had to deal with a clueless vet, I can completely relate!