Does the service animal have to wear a vest or identifying harness? No. Under the ADA service animals are not required to wear a vest, ID tag or harness.No. The ADA does not require service animals to wear a vest, ID tag, or specific harness. Arizona and federal law allow you to bring service dogs, but not emotional support animals, to all public places. Do service animals have to wear a vest or patch or special harness identifying them as service animals? A service dog should be wearing a vest that identifies it as such and, in some locations, they must also display an official tag or ID card. Answer a few simple questions. This publication provides guidance on the term "service animal" and the service animal provisions in the Department's regulations. A dog walking contract should outline the dog walker's major responsibilities and the process for carrying those out.