How Long Does ESA Last? March 11th, 2021 Each ESA letter is valid for 12 months after you obtain them from a certified health professional. After one year, you will have to renew your support animal letter. Related Posts How Long Do Dogs Stay Pregnant? Common Dog Pregnancy Guide Tips Can You Give Fexofenadine to Dogs Suffering from Allergies? What do Autism Therapy Dogs Do? Dog Flea Home Remedy Guide [therapypet_step1_form show_in_mobile="1"]