28 CFR Part 35 Title II Notice of Proposed Rulemaking (NPRM) (published 2008)

(b) Exceptions.  A public entity may ask an individual with a disability to remove a service animal from the premises if:

(1) The animal is out of control and the animal's handler does not take effective action to control it;

(2) The animal is not housebroken or the animal's presence or behavior fundamentally alters the nature of the service the public entity provides; or

(3) The animal poses a direct threat to the health or safety of others that cannot be eliminated by reasonable modifications.