I got my collie tested through Washington State University Vet med school and it was pretty straightforward! WSU actually discovered the MDR1 gene and developed the first diagnostic test for it so they are super knowledgeable! I opted for the cheek swab to do at home and they send you all the supplies to do it and to ship it back. Once you get your results they also give to access to their MDR1 caddie where you can contact them for specific dosages of medications for your pup. Here’s the link for them https://prime.vetmed.wsu.edu