It's Dachshund (transl. Badger dog) not Daschund (transl:the trash).It is a very nice looking dog, but it is a mix, not a breed.
Mathilda, you will have to explain your theory more. I'd think that if as a breed the daschund has back problems because of how long it's back is in relation with it's size in general, that crossing with a dog with a more normal back would reduce the risk of back issues.
On a side note, the mixed dog remindes me of the Drever and the various Dachsbracke breeds, which are similarly structured, just not with that coat type.
At first glance, I thought it looked a lot like a long haired Dachshund , too. I was actually leaning towards maybe Dachshund/Cocker Spanieal until I took a second look. I can definitely see Golden in the head and fore quarter....Other than the size, I'd almost buy that do in the picture was a long haired dachshund. It looks decently proportioned, actually.