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Health Testing Guide
Which tests are mandatory, how to spot responsible breeders — and what it costs when things go wrong.
For the Leonberger we've compiled 9 core tests (8 of them required by Deutscher Club für Leonberger Hunde e.V.) and 1 additionally recommended test, drawn from breed-club regulations, the University of PEI (CIDD), and OMIA — weighted by severity and heritability.
View verified breedersWhat this grade means
In the Leonberger, size and genetic predispositions carry significant risks for hip dysplasia (HD), elbow dysplasia (ED), and severe neurological disorders such as polyneuropathy 1, polyneuropathy 2, and leukoencephalomyelopathy. A responsible breeder counters this proactively and uses the mandatory genetic tests and X-ray examinations of the Deutscher Club für Leonberger Hunde e.V. prior to mating. Have the official test results of the parent animals shown to you: for HD, only A–B is permitted, and for ED, only 0–1; for polyneuropathy 2, both parents must be clear, and for polyneuropathy 1 as well as leukoencephalomyelopathy, a carrier may only be mated with a clear partner.
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. The core standard for the Leonberger covers 9 tests, 8 of them required by Deutscher Club für Leonberger Hunde e.V., plus 1 additional recommended test. 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 don't always predict severity in the puppies. Even so, they're a powerful tool of responsible breeding.
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.
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 meets the Good level and performs 1 additional clinically recommended screening that reduces risk in this breed.
In addition to Good:
Dilated cardiomyopathy(DCM)
Herz
Dilated cardiomyopathy (DCM) is a severe disease of the heart muscle where the heart's chambers become stretched and enlarged. This stretching thins the heart walls, making it difficult for the heart to pump blood effectively to the rest of the body. Over time, this decreased pumping ability can lead to fluid buildup in the lungs or abdomen.
Ultrasound · Passing: normal
Not health tests, but required for breeding: the club asks for these results too. They don't count toward the risks or the rating.
DNA-Identitätsnachweis
Required by Deutscher Club für Leonberger Hunde e.V.
Acceptable result: DNA-Profil liegt vor
Wesensbeurteilung
Required by Deutscher Club für Leonberger Hunde e.V.
Acceptable result: Gültige Körung
Dental and bite evaluation
Required by Deutscher Club für Leonberger Hunde e.V.
Acceptable result: Vollständiges Gebiss (bei M3-Verlust muss der Partner vollzähnig sein)
These levels are a comparison framework, not an official certification. They help compare breeding programs at a glance.
A complete checklist with every core-standard and additionally 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 — Elbow Dysplasia
Both parents must be ED 0–1 or better.
We take mandatory tests from official breed regulations, build the recommended health standard from veterinary databases — and cross-check every uploaded certificate against the dog's profile using AI.
L1 = core standard: the club's required tests where its rules set them, otherwise the recommended health standard for the breed. L2 = additionally recommended or clinically indicated. L3 = lower prevalence. Every assignment carries a source and confidence rating.
VDH breeding regulations, CIDD (University of PEI), OMIA (University of Sydney), curated veterinary input.
Uploaded certificates are read by AI and checked for date, result, and consistency with the dog's profile — our team reviews anything inconclusive.
The Leonberger is not currently listed in our extreme-breeding overview. That does not mean it is free of hereditary disease: which ones are typical, and which tests the parents should have, is on this page.
Self-check
Answer 6 quick questions about your everyday life and see how well the Leonberger fits you — including an honest cost estimate per month, per year, and across the dog's lifetime.
See breeders who have already uploaded their health test results for verification.
View verified breeders