Can a landlord tell other tenants about my ESA?

The rule

Information about an accommodation request should be used to evaluate the request and not shared more widely. Telling other residents that you have a disability, or that your animal is there on medical grounds, is a disclosure that serves no legitimate purpose in evaluating anything.

What neighbours can legitimately be told

That the animal is permitted. That is all that is required to answer the complaint a neighbour is usually making, which is that the building has a no-pets rule and somebody has a dog. A provider can say the animal is there with permission and stop, and a good one does.

If it has already happened

• Write to the provider, say what was disclosed and to whom, and ask them to confirm in writing that it will not be repeated.
• Keep the record. If anything later goes wrong with the tenancy, a prior improper disclosure is relevant context.
• Where the disclosure has led to harassment from other residents, that is a separate and more serious problem, and interference with a fair housing right is itself unlawful.

The competing-allergy case

Where a neighbour has an allergy the provider has to manage both situations, and that may require telling them an animal will be present. It does not require telling them why you have one.