I saw a couple people I follow reblog a post about registering your animal(s) as service animals to make sure you can’t have your animals taken from you and it included a link to a place called the National Service Animals Registry. DO NOT DO IT, it is a scam!
For one, it is a dot com, which should be a big red flag! Two, it charges you to register your pet ($65!!!!!). Three, people can register ANY animal with it (including aggressive animals!)and not ones that are trained to deal with health/mental issues.
Just google it and you can see some webpages that call it (and other similar sites) out for being scams.