Whatever he is, he's in good shape. His weight looks great! We had someone stop in about a month ago or so and ask the same question. I was CERTAIN that THAT dog had Basenji in it. She had him DNA tested and I was dead wrong. Not even a little bit of Basenji. So... I just don't know. If you do have him tested, please come back and share the verdict!
If you decide on a DNA test use Embark instead of Wisdom. I think Embark's breed data base is supposed to be more accurate. There is a Reddit group where people post DNA results on their dogs. Sometimes the results are hilarious. Occasionally someone will get results from both Embark and Wisdom with wildly different breeds listed. You can search by breed within the group, r/DoggyDNA.