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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 Norwich Terrier we've compiled 1 test required by Klub für Terrier von 1894 e.V. and 4 additionally recommended tests, 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 Norwich Terrier, the health profile is primarily defined by orthopedic vulnerabilities as well as eye and respiratory problems: patellar luxation (PL), primary lens luxation (PLL), cataracts, and upper airway syndrome (OLS, ADAMTS3-associated) are among the relevant risks, complemented by the risk of a portosystemic shunt (hepatic encephalopathy). The Klub für Terrier von 1894 e.V. strictly mandates screening for patellar luxation (PL) for breeding, where only values of PL 0–1 are permitted. Health-conscious breeders additionally test their breeding stock for cataracts, evaluate the risk of upper airway syndrome (OLS, ADAMTS3-associated) as well as a portosystemic shunt (hepatic encephalopathy), and verify the status for primary lens luxation (PLL). Have the proof shown to you before purchasing: the PL results of both parents, eye examination results clear of cataracts, an unremarkable finding regarding a portosystemic shunt, and the status for primary lens luxation (PLL) – a carrier should 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. For the Norwich Terrier, Klub für Terrier von 1894 e.V. requires 1 test for breeding approval, plus 4 additional recommended tests. 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 4 additional clinically recommended screenings that reduce risk in this breed.
In addition to Good:
Upper airway syndrome (UAS), ADAMTS3-related(OLS)
Atmung
Upper airway syndrome is an inherited respiratory disorder where fluid buildup and tissue swelling (edema) narrow the throat and voice box (larynx). A mutation in the ADAMTS3 gene disrupts fluid drainage in these tissues, restricting normal airflow into the lungs. Because inheritance is complex, this gene variant serves as a major risk factor rather than the sole cause of the disease.
Physical examination · Passing: OLS-0, OLS-A, OLS-B
Cataract(HC)
Augen
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.
Eye examination · Passing: clear
Lens luxation(PLL)
Augen
Lens luxation is an inherited eye disorder where the lens slips out of its normal position because the supporting fibers holding it in place weaken or break. When the lens shifts, it can block the natural drainage of fluid within the eye. This blockage causes a rapid, painful buildup of pressure called glaucoma, which can lead to permanent blindness if left untreated.
Eye examination · Passing: clear or carrier
Portosystemic hepatic encephalopathy(PSS)
Stoffwechsel
This is a neurological condition caused by liver dysfunction, typically occurring when abnormal blood vessels bypass the liver. Because the liver cannot filter toxins from the bloodstream, these harmful substances build up and directly affect the brain. This lack of proper filtration leads to central nervous system dysfunction.
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 Klub für Terrier von 1894 e.V.
Acceptable result: DNA-Typisierung durchgeführt und in Genotypen-Datenbank hinterlegt
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 — Patellar Luxation
Both parents must be PL 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 Norwich Terrier 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 Norwich Terrier 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.
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