Oh to be clear, I think it's perfectly plausible (and even likely). You can boil the question down to "does smelling a female in heat lower impulse control in intact males", and, well, yeah, I can believe that without batting an eye. But it was a convenient place to make a larger point about the lack of good evidence in a lot of veterinary medicine, which I think is something we should talk more about (I'd levy the same critique against medicine for people, too!). Anyways, I probably should have been clearer in my original post, that my point was really: it seems completely plausible, but we need to be better about citing research in medicine and being explicit about corresponding confidence levels, and veterinary research is woefully under-funded.
I think my personal biggest complaint about the overwhelming prevalence of desexing in the US is that we're not really being honest with ourselves about why we're doing it. I would argue, based on my experience, (I realize the hypocrisy in using sociological anecdata immediately after complaining about medical anecdata), the vast majority of pet owners who desex their dogs do so out of convenience, and the vast majority of policy encouragements for it (eg: shelters requiring it or cities assessing 10x licensing fees for intact dogs) are done because most US dog owners aren't responsible enough to prevent unwanted pregnancies and have a horrible habit of abandoning unwanted litters. That's not to say that there aren't medical reasons; some of them are even on really solid footing (eg using spaying as a way to stop frequent painful false pregnancies), but I don't think most US dog owners are even aware of that being a thing, much less making medical decisions in response to it.
I think we are starting to see a discussion of sterilization vs desexing, which is great, but even so, as it stands today, spay/neuter is standard practice in the US. I almost never see an acknowledgement that, particularly for females, we've more or less mandated a very substantial, very invasive medical procedure, mostly just because dog owners in the US just don't want to deal with a particular part of canine biology. And I personally think that raises ethical concerns around treatment of animals.
Also, thanks! She's an almost-90-pound ridgeback, so... running is one of the few things keeping us (relatively) sane!