We group breeding programs into three levels based on testing depth. Ask your breeder directly which level they meet.
A breeder at the Great level performs all mandatory tests plus 6 additional clinically recommended screenings that reduce risk in this breed.
In addition to mandatory tests:
Cataract(HC)
Augen und Sehvermögen
A cataract is a progressive clouding of the lens inside the dog's eye, which is the clear structure that focuses light onto the retina at the back of the eye. When the lens becomes cloudy or opaque, it blocks light from entering, gradually impairing the dog's vision. If left untreated, this condition can eventually lead to complete blindness in the affected eye.
Augen · Passing: CLEAR
Hip dysplasia(HD)
Bewegungsapparat
Hip dysplasia is an inherited skeletal disorder where the ball and socket of the hip joint do not fit together properly. Instead of sliding smoothly, the bones rub and grind against each other, wearing down the protective cartilage. Over time, this chronic friction causes joint instability, painful inflammation, and progressive arthritis, which is the gradual wear and tear of the joint.
Roentgen · Passing: FCI A or B
Patellar Luxation(PL)
Bewegungsapparat
Patellar luxation, also known as a luxating patella, is a physical condition affecting the knee joint where the kneecap slips out of its normal groove. This misalignment interferes with the mechanical movement of the hind leg and can cause the joint to lock. Over time, this abnormal friction can lead to painful joint wear and tear, known as osteoarthritis.
Physisch · Passing: Grad 0 or 1
Hereditary Necrotizing Myelopathy(ENM)
Nervensystem
Hereditary Necrotizing Myelopathy (ENM) is a severe genetic disease affecting the spinal cord, specifically linked to a mutation in the IBA57 gene in the Kooikerhondje breed. This mutation causes the progressive destruction (necrosis) of nerve tissue in the spinal cord, which blocks vital signals between the brain and the limbs. Because it is inherited in an autosomal-recessive manner, a dog must inherit the mutated gene from both parents to be affected.
DNA · Passing: Clear or Carrier
Kooikerhondje Kidney Disease(KND)
Nieren
Kooikerhondje Kidney Disease is a severe condition affecting the renal system, where the functional tissue of the kidneys is progressively destroyed. As this tissue is lost, the kidneys can no longer filter waste products from the blood, eventually leading to chronic kidney failure. Although the disease is specific to the Kooikerhondje breed, its exact inheritance pattern is currently unknown.
Passing: Clear or Carrier
von Willebrand's disease(vWD)
Stoffwechsel
Von Willebrand disease is an inherited bleeding disorder that affects the blood's ability to clot properly. It is caused by a deficiency or malfunction of the von Willebrand factor, a specific protein that helps blood platelets stick together to plug damaged blood vessels. Without enough of this functional protein, the clotting process is delayed, which can lead to excessive bleeding even from minor injuries.
Passing: Clear or Carrier
These levels are a comparison framework, not an official certification. They help compare breeding programs at a glance.
A complete checklist with every mandatory and recommended test plus identity and rearing questions — take it with you.
Open the full checklistFor breeders
Machine-readable mating rules, minimum ages, scoring schemes, and what's required for HonestDog verification — as a printable guide.
Example rule — Wesensbeurteilung
Both parents must be tested for Wesensbeurteilung and show a passing result.
We compile mandatory tests from official breed regulations and veterinary databases — and check every uploaded certificate for authenticity.
L1 = mandatory under breed-club regulations. L2 = recommended or clinically indicated. L3 = lower prevalence. Every assignment carries a source and confidence rating.
VDH-Zuchtordnungen, CIDD (University of PEI), OMIA (University of Sydney), curated veterinary input.
Uploaded certificates are AI-extracted and reviewed by our team for authenticity, date, and result.
1 tests are currently mandatory under the relevant breed-club regulations. The most common are Wesensbeurteilung. Every test must be completed before mating, and the result must fall within the threshold defined by the regulation.
See breeders who have already uploaded their mandatory tests for verification.
View verified breedersHealth Testing Guide
Which tests are mandatory, how to spot responsible breeders — and what it costs when things go wrong.
For the Dutch Kooikerhondje we have compiled 1 mandatory and 6 recommended health tests, drawn from breed-club regulations, the University of PEI (CIDD), and OMIA — weighted by severity and heritability.
What this grade means
The Nederlandse Kooikerhondje is a vital breed, but it is susceptible to specific hereditary conditions due to a historical genetic bottleneck. Thanks to consistent breeding tests, the fatal Kooiker paralysis (Hereditary Necrotizing Myelopathy) and Von Willebrand disease (a blood clotting disorder) are now very well controlled. When purchasing a puppy, you should also check the patellar luxation status of the parent dogs.
Every breed is susceptible to certain inherited conditions. Just like humans, dogs inherit predispositions from their parents. Responsible breeders screen their breeding dogs for these conditions and make informed mating decisions to reduce the risk passed on to puppies.
No — but it's the strongest tool we have. Diet, exercise, environment, and genetics all contribute to whether a dog develops a condition. When breeders use the right tests to identify risk in potential parents, the likelihood of many conditions appearing in the puppies drops significantly.
There's no one-size-fits-all here. For the Dutch Kooikerhondje we track 1 mandatory tests plus 6 additional recommended ones. The specific tests and passing thresholds are detailed further below.
Keep in mind
Reliable screening tests still don't exist for many hereditary conditions, and tests for complex polygenic conditions are not always predictive of severity in the puppies. Even so, they're a powerful tool used by every responsible breeder.
There are two main types of health tests:
Screen the dog's DNA for known disease-causing mutations. Can be performed from puppyhood and give a binary result (clear / carrier / affected).
Clinical and imaging exams like X-ray, ultrasound, or ophthalmoscopy. They show how a predisposition actually manifests — usually only conclusive after 12–18 months.