Three templates for service dog letters from healthcare professionals, covering the types of letters service dog users may legally need. Choose between PRINTED or ONLINE.All of this and more is outlined in a contract or service agreement to prevent headaches and confusion down the road. To avoid these potential consequences, landlords and tenants should consider using a Pet Addendum whenever pets are allowed in a rental property. 12 McCandless Ave Pittsburgh, Pennsylvania 15201. The Service Agreement is the primary document and foremost element of any dog walking contract. Is the same definition of "service animal" used under Pennsylvania.