
Both parents should have been DNA tested for or have a hereditary status re PRA cord1 and that pairing won't produce affected pups.
I have only had mini longs and they are the more laid back of the 3 coats, yes they bark but not at everything, only things they don't recognise, they can be stubborn at times but on the whole very devoted and loving.
Other health issues are back problems but if you research the lines and pick a pup from parents with ancestors who have had no problems before the age of 6yrs then unless injured are less likely to develop problems later in life, how they are raised from puppyhood and what exercise they are allowed to do when young also impacts on their spine staying healthy, I don't know if smooths have more problems as they haven't been mixed with another breed.
Epilepsy with no obvious cause can also appear, there is a research study going on at the moment into that and diet being the cause.
There are puppy farms out there producing dachsies and as I found some even belong to the breed clubs,so do your homework.
Good Luck with your search.