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.The Red Vest designation recognizes places that are welcoming and accessible to people with disabilities and are committed to public access rights. 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. No. The ADA does not require service animals to wear a vest, ID tag, or specific harness. Because service animals are not required to wear vests, a dog that is wearing a vest is not necessarily a service animal. This article provides information about the legal differences between emotional support animals and service animals in the state of Arizona. An Assistance Animal must be contained within the Owner's privately assigned individual living accommodations (e.g. MultiYear Contracts. A. Specified Period.