Health Testing Guide
Which tests are mandatory, how to spot responsible breeders — and what it costs when things go wrong.
For the Biewer Terrier we have compiled 8 mandatory and 4 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 Biewer Terrier is generally in solid health, with patellar luxation being the primary concern for breeders. As with many toy breeds, you should also be mindful of dental misalignments and tracheal collapse, which can cause issues in daily life. If the parent dogs have documented healthy knees, you are choosing a quite robust companion.
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 Biewer Terrier we track 8 mandatory tests plus 4 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.
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 4 additional clinically recommended screenings that reduce risk in this breed.
In addition to mandatory tests:
Legg-Calvé-Perthes disease(LCPD)
Bewegungsapparat
Legg-Calvé-Perthes disease is a serious orthopedic condition affecting the hip joint, primarily in small breed dogs. It occurs when the blood supply to the head of the thigh bone, known as the femur, is spontaneously disrupted. Without blood, this bone tissue dies and collapses, leading to severe joint inflammation and pain.
Roentgen · Passing: Normal
Degenerative Myelopathy(DM)
Nervensystem
Degenerative Myelopathy is a progressive disease of the spinal cord where the protective sheath around the nerves slowly breaks down. This deterioration disrupts the vital communication signals between the brain and the muscles of the hind limbs. Over time, this lack of signal transmission leads to a complete loss of muscle control in the back legs.
DNA · Passing: Clear or Carrier
Hyperuricosuria(HUU)
Nieren
Hyperuricosuria is an inherited metabolic disorder affecting the renal system, specifically how the kidneys process uric acid. Due to a genetic mutation, excess uric acid is excreted into the urine rather than being broken down. This high concentration can cause the acid to crystallize, leading to the formation of painful bladder or kidney stones, also known as uroliths.
Koerperfluessigkeiten · 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
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 — Patellar Luxation
Both parents must be 0 or better.
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 breeding regulations, 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.
8 tests are currently mandatory under the relevant breed-club regulations. The most common are Brachycephalic obstructive airway syndrome (BOAS) (BOAS), Progressive Retinal Atrophy 1 (Golden Retriever) (GR-PRA1), Progressive Retinal Atrophy (PRA) (PRA). 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 breeders