The Wetterhoun is a hunting dog from the Netherlands. It's a water retriever and has a curly coat somewhat like a poodle. It was used for hunting polecats and otter, retrieving birds, and also as a watchdog.
It is a rare breed. It doesn't have much genetic diversity.
Always in the past kennel clubs have kept on insisting to breed purebred to purebred, and their 'solution' to the growing amount of health problems was to screen dogs for health issues and only breed healthy individuals. Problem is, if you don't have much genetic diversity to start, you can accidentally exclude dogs with more diverse bloodlines. Example, one great-grandparent dog had great hips, and most of his kids, grandkids, etc did as well. If you only breed dogs with great hips, you are probably only breeding his great-grandkids to eachother, probably addressing 1 health problem and causing 100 more.
The Dutch are finally realizing what so few do. You can't fix the problem this way.
They are doing outcrossing.
There are two main things they are doing.
They are holding 'Wetterhoun look-alike contest'
This is where people bring wetterhoun who came from unregistered parents, or are half or 3/4th wetterhoun and carry the same looks/behaviors....or are mutts of uncertain lineage but by appearance/behavior are most likely of wetterhoun blood. This is great because it increases the base of overall genetically diverse individuals. In essence, if you go back up these dog's pedigree you'll find a pure wetterhoun, one who may not have had any 'officially registered' offspring still represented in the current dogs. Plus, it's likely bringing in genes in small amounts from dogs that have no relation to the wetterhoun.
They are doing planned outcrosses.
This is where they take a group of registered wetterhoun and purposely breed them to another breed, take these half-breeds and breed them to other wetterhouns, and then when they reach either 3/4th wetterhoun or 7/8ths wetterhoun, choose the individuals who are of the wetterhoun type and treat them as 100% pure. There's a planned outcross with the Airedale Terrier and the Shikoku from Japan.
It's this kind of 'radical' thinking by kennel clubs that needs to be applied if there is any hop of pulling back from the brink of destruction so many generations of restricted inbreeding has brought us to.