You should always go to the primary source.
Here's the Vaccine paper [1,2]. I don't say this often about papers, but this is total crap. They did a YouGov survey of 2200 people, and HILARIOUSLY, 84% of respondents stated that their dog was up-to-date on the Rabies vaccine (another 5% weren't sure.)
Oopsie! No matter...they just barge ahead with their pre-determined conclusions, and make a model of "Canine Vaccine Hesitancy" based on these responses anyway. BTW, I see no support for the claim that "40% believed canine vaccines were unsafe". The closest survey response is this one, at 30%:
> Most vaccines that dogs receive are not medically necessary
(You'll note that this is not a question about the Rabies vaccine. Just vaccines in general. And, of course, your guess is as good as mine what "most" means.)
The whole paper is almost designed to create a narrative of "vaccine hesitancy amongst pet owners" -- it asks some questions about how people feel about animal vaccine mandates and safety in general, then tries make a a model to predict negative responses (which they call "CVH"), and then they use that to predict opposition to mandatory vaccine policies.
At no point do they actually deal with the fact that the vast majority of their respondents, regardless of opinion, actually vaccinated their pet for Rabies. I don't know if Vaccine is a good journal, but this is just a classic example of a paper that should never have made it past peer review.
[1] https://www.sciencedirect.com/science/article/abs/pii/S02644...
[2] (full text of draft here, where you can see the data) https://ideas.repec.org/p/osf/socarx/qmbkv.html