Q31. Are stores required to allow service animals to be placed in a shopping cart?
A. Generally, the dog must stay on the floor, or the person must carry the dog. For example, if a person with diabetes has a glucose alert dog, he may carry the dog in a chest pack so it can be close to his face to allow the dog to smell his breath to alert him of a change in glucose levels.
Americans with Disabilities Act Questions and Answers: Service Animals
Sorry in a hurry, but I did found this. Will post more later.