How to prove a dog is purebred without papers? DNA testing is one easy way to determine whether your Pom dog is a true full-breed Pomeranian. This is the only way to prove the breeding without the necessary paperwork. This type of testing has become extremely advanced in recent years. Many kennel clubs won’t register a dog unless a DNA test has been carried out. It’s not complicated or expensive to do. Numerous companies can do this DNA testing, and more are constantly rising. The most common test is to do a mouth saliva swab. The sample is sent off for analysis, and the results will come back 2 to 4 weeks later. Most vets can do this test for you.