
Before I started breeding I thought there was only 2 options, mate unrelated dogs[good] mate very closely related dogs [bad] then I learnt that there was linebreeding[between the previous 2 options] and with help of a mentor have been helped to pick the right studs for my girls as they had over 20yrs knowledge of the breed and the various lines bred by the serious ethical breeders and what could work, no guarantee, and what to stay away from.
My breed was hit hard when the trial results for DNA testing for PRA cord1 was announced in Feb 2005 because there were so many affected dogs and few clear results, some kennels threw in the towel, others retired their affected dogs[later when everyone realised that affected dogs can still be included provided the mate was clear it was too late for those dogs who had been neutered] and waited to buy in clear or carriers, relying on stud owners to let them use their clear males on their their carrier bitches, there were long waiting lists for bitch pups in particular,even those who had been in the breed for years having to wait 2yrs or more and then accept a carrier. I got my first male dachsie in 2004, when he was 6 months old I started looking for a suitable bitch, he was nearly 2.5yrs old before a small time breeder trusted me enough to get one of her PRA clear bitches and became my mentor and introduced me to many show/ breeders.
Many pedigrees have the top studs of the day on them, these dogs took part in the trials back in the 90's, one turned out to be PRA clear but his top stud son was a carrier, they had passed on to the Rainbow Bridge before the testing was rolled out for general use, so there was alot of very close breeding going on to build up the gene pool, now we can't register fathers and daughter or mothers and sons pairings.
When researching pedigrees you have to rely on everyone being honest about any problems in their lines, unfortunately not everyone is and it is hard to find out what happened to the pups sold as pets and therefore not shown or bred from as they may be hiding some hereditary problem.
So which ever option you choose, linebreeding or out crossing you need to do your homework and even then things can go awry.