In my opinion, it doesn’t matter whether the ducks are “service ducks” or just pets, and whether the kid has autism or not.
They have a couple of ducks on their own property that aren’t hurting anybody, so to keep them. they should be allowed to keep them.
The town is way off base here. A yelping dog makes a lot more noise than a couple of quacking ducks. It is not like he is keeping them in a bathtub in an apartment building.
My daughter worked with autistic kids. She mentioned that little things like pets, board games, tossing a Frisbee (iow, things involving interaction with other living things) really, really helped autistic kids. Unfortunately, about two thirds of their parents were mostly interested in keeping the government checks coming and ignored her advice. They substituted big screen TVs, video games and other electronic gadgets which had the exact opposite effect.
These parents sound like the third who were great parents and want to help their son. The town Nazis need to back off.
FWIW, one of my favorite fast food places in town (a Wendy's) employs an autistic young lady. She is constantly cleaning up, getting drink refills or condiments for the customers and cheerfully doing whatever is asked. If nothing is being asked of her, she visits the customers (or other staff) and solicits duties.
You never see her standing outside and getting drags on a cigarette or buried in a cell phone texting like most fast food workers her age.
Indeed time to give them a teddy bear a blanket and a sucker to keep them calm.