Here is my small unit on Assistant Animals. Students are to compare/contrast Service vs. Therapy animals. I have attached the worksheet on that as well. I also have an assignment the students are to complete as well which involves them contacting organizations which trains either service or therapy animals. You can find the assignment at the end of the PowerPoint. I also go over the FAQ on Service Animals which can be found on the ADA website. I have also attached those questions as a worksheet. Another attachment I have included is about faking service animals. We have an open class discussion after the students read the article and we discuss the issues Service Animal Owners face and the problems with faking a service animal. I hope some of this material helps you out.
I have a person who trains therapy dogs (and utilizes them in Animal Assisted Therapies- mostly with children in cancer wards) talk to the students about the differences between service animals and therapy animals. I also have a friend with a non profit called Dogs2dogtags (on Facebook and has a website if you want to contact) that trains service dogs for PTSD soldiers that we Skype with.
I think this is an extremely important and growing issue and it is essential to teach the students the difference.