How does this change anything?
If someone has a problem with dogs, or anything else, then they are not qualified to perform a job that requires interacting with dogs, or whatever their particular disability involves.
They aren't being denied a right to work out of discrimination or prejudice. They simply can't do that job.
Here's the difference between that and prejudicial discrimination:
If someone does have either an allergy or tramatic stress issue with dogs, or whatever else, but for some reason they really want to do this particular job anyway, they still can. IF they want to deal with their problem theirself somehow, with allergy meds or meditation or plain iron will or whatever, as long as they can and do the job properly, no one will prevent them.
Discrimination & prejudice is I don't care how good you might be at the job, you still aren't allowed to do it (or are significantly and artificially disadvantaged) simply because you're female or black etc.
The drivers just don't like that the dogs mess up their cars and the smell displeases the next customer and affects their rating and tips.
The answer to that is tough shit. Don't take a job serving the public if you only like some people and not others.
This is the general store mysteriously always being out of flour or beans for the black family. Your freedom not to interact with people you don't like and who aren't violent or otherwise dangerous, comes only in the form that you are free not to operate or work for a business that serves the public. Go be a comic book artist or accountant or something where you don't have to let any filthy dogs into your house as part of your job.