It is important to understand what is considered a service animal. Under the federal Fair Housing Act (FHA), it doesn’t matter what you call them (service animals, companion animals, therapy animals, working animals, etc.); if the animal exists to serve the individual’s disability it is not legally a pet and may not be treated as such. This means no pet fees, pet deposits, or pet rent is permitted. A landlord may not restrict such animals by breed or species in housing. A landlord may not request or require proof of training or certification for such animals in housing. A landlord may have assistance animal rules as long as they’re no more restrictive than any pet rules that apply to all other tenants.
Any other accommodation / modification requests, the disability-animal request must, too, be “reasonable” and the resident is responsible for their animal. That means that a landlord would be within their rights to respond to the service bird that shrieks at two in the morning, the companion cat that attacks other residents, or the seeing-eye-dog that soils the carpet.