I understand you may have to pull over and vacuum your car but beyond that those dogs are trained well. Drivers other option is to carry a aheet or blanket and put it down on the seats. The only other issue I see is if your allergic to dogs but unfortunately its part of the job. You know when you sign up that there is the possibility of getting a passenger with a service animal. Stop being a jerk! Whatever you do dont complain the whole ride about the dog. How would you feel if you were treated this way or a family member? So rude and inconsiderate!
We are required to take these rides. However we are not required to transport pets or "emotional support animals". True service dogs are trained very well and will not cause any issues in your car (other than some hair) which is easily taken care of. Be a decent human being. You should be suspended with 1st offense and deactivated if you continue to cancel.