Two Questions the ADA Allows To Be Asked
The ADA permits two questions to be asked of a person accompanied by an animal (unless the disability is obvious, in which case questions are prohibited.) If the animal meets the criteria, the animal should be allowed to accompany the individual to all areas where anyone is normally permitted to go. The two questions are:

Please just let us know Is the animal required because of a disability.
What work or task has the dog/miniature horse been trained to perform?

When an Animal May Be Denied Access to an ADA-Covered Facility
While an individual who doesn’t have an apparent disability may be asked the two permitted questions and those with an apparent disability can’t be asked these questions, there are circumstances in which an animal may be denied access:

The animal is out of control and its handler doesn’t take effective action to control it.
The animal isn’t housebroken.
The animal poses a direct threat to the health or safety of others that can’t be eliminated or reduced to an acceptable level by a reasonable modification to other policies, practices, and procedures.