Speak to your doctor. If they agree that the animal is necessary for your treatment, they can write you a letter. It is important to think about why you need the letter.If it is because you live in housing that otherwise does not allow pets and your doctor believes it is important to keep the animal with you, then it must be stated in the letter that the animal is required to live with you continuously as part of your treatment. Your specific condition does not have to be mentioned.If the letter is needed for air travel, and your doctor is in agreement that you need an ESA to stay with you, call the airline and ask them exactly what they need. Some require the letter be less then one year old from date of travel, some require newer. Because airline policies change often, this answer would become dated fast if I went into specifics.The important thing to remember is that an animal is a lot of work. The care of an animal does not fit into everyoneu2019s treatment plan. Your doctor will help you decide if an ESA would be beneficial to you.