First of all, an emotional support animal is a pet holding by any person at their home and a pet animal is prescribed by the mental professionals such as therapist, psychiatrist, psychologist, and like more.
But, those professionals should be licensed to treat you and prescribing pet animals too. For example, if you have been suffered from mental illness, and then your pet animal involves in your treatment program. In order to involve your pet, the doctor prescribes the animal. So, your pet animal will reduce the negative symptoms and as well as emotional disability.
What animals qualify to be an ESA? Almost all domesticated animals such as cats, dogs, birds, rats, mice, rabbits and so on, are used in the emotional support animal letter. In addition to that, those animals can be in any age from puppies to adults. The best part about this treatment is, there is no need of training to find out your disabilities.
But, the only thing that you need to keep in mind is your pet should be manageable in public so that pet is qualified to use the treatment. Each state has some laws in this treatment to carry animal along with you.