Can a building or co op make you carry your service dog in the building?

No, a building or co-op cannot legally require you to carry your service dog. Under the Americans with Disabilities Act (ADA), individuals with disabilities have the right to have their service animals accompany them in all areas where the public is allowed. However, if the service dog is not trained to perform specific tasks related to the handler's disability, it may not qualify as a service animal, and different rules could apply. Always check local regulations and policies, as they may vary.