[HWR_14]

Animal allergies (as opposed to asthma triggered by animal dander) is only considered a disability is it actively affects your ability to breathe or otherwise function in pretty basic ways. So, yes, under the ADA in the US, denying someone employment with allergies is fine but refusing to give rides to service dogs is not.

Of course, a simpler solution would be to have Uber choose an appropriate car that was willing to give rides to service animals.