Let's talk about Disability Service Dogs.

If you want to know what the FEDERAL LAW says, search for the Americans with Disabilities Act, and there is about one page that covers Service Animals in Title III of the ADA.  This is on the U.S. Department of Justice website. 

At this point in time, only dogs and miniature horses can LEGALLY be used per FEDERAL LAW.  Remember, federal law takes precedence over state laws, and state laws take precedence over local regulations.  Your duck may be legally recognized as a Service Animal in your state, but don't count on it elsewhere.  Federal law is the final word. 

Disability Service Animals are different from Emotional Support Animals.  A DSA must be able to perform three specific tasks for their human partner, per the federal court's interpretation of the ADA.  However, someone cannot ask the human partner to demonstrate this.  (It's kind of difficult to signal a seizure if none is immanent.) 

A business may ask a person if the animal is a DSA, but they cannot ask what one's disability is or how the dog "works."  To do so not only violates the ADA, it also violates the medical privacy act, HIPPA. One's medical information is between the patient and the doctor, and random third parties are not entitled to that information. 

Please do not pet, talk to, or otherwise distract a DSA.  Ignore the animal!  Let the animal do the work it was trained to do. 

And absolutely do not feed the DSA. 

All DSAs have equal "free access" under the ADA.  No one kind has more access than others.  A restaurant cannot seat the person with a DSA in a segregated area, a hotel cannot deny a room or charge an extra fee, and the federal courts have ruled that allergies are not a reason to deny access.  Besides, the only allergens are the dander from the skin and saliva.  DSAs are bathed regularly, given flea treatments, etc., and they aren't licking random third parties, so allergies just are not an issue. 

Churches and religious institutions are exempt from the ADA under the First Amendment, however, most churches allow not only DSAs but also DSAs in training. 

Using a DSA is not only a right of a person with a disability, it is also a responsibility.  The disabled person KNOWS already that they are supposed to clean up after their dog, that their dog is not to run lose, etc.  It is insulting to make these suggestions to persons with disabilities.  They are usually highly responsible individuals who have been trained in how to care for their animal.

Miniature horses are proving to be highly accomplished guide animals for the blind, and yes, they are house-trained.  They are sometimes used for wheel chair assistance. 

A federal court in Oregon ruled that breed restrictions are unconstitutional because they are not based on fact.  Yes, there are pit bull terriers trained for DSA work.  A small dog can perform DSA tasks, especially for persons with seizure disorders, diabetes, deafness and PTSD.  I have seen a video of a Jack Russell Terrier who is positively amazing.  This little guy even brings in the mail, then returns to the mail box to close it. 

If you want to know more, go to the Department of Justice's website and look up the Service Animal section of the Americans with Disabilities Act.