Loading health guide
Health Testing Guide
Which tests are mandatory, how to spot responsible breeders — and what it costs when things go wrong.
For the West Highland White Terrier we have compiled 10 mandatory and 11 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 West Highland White Terrier is rated with a grade C due to an above-average predisposition to eight known hereditary diseases. The eyes are particularly at risk from conditions such as Progressive Retinal Atrophy (PRA) and glaucoma, which necessitate regular screenings. Additionally, patellar luxation is a known musculoskeletal issue that should be ruled out by ensuring both parents are healthy before purchasing a puppy.
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 West Highland White Terrier we track 10 mandatory tests plus 11 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 11 additional clinically recommended screenings that reduce risk in this breed.
In addition to mandatory tests:
Persistent pupillary membranes (PPM)(PPM)
Augen und Sehvermögen
Persistent pupillary membranes (PPM) occur when tiny blood vessels that nourish the eye's lens before birth fail to break down and disappear as they normally should. This leaves behind delicate strands of tissue that stretch across the iris, which is the colored part of the eye, and the pupil. In some cases, these strands can attach to the cornea, the clear outer layer of the eye, or the lens.
Augen · Passing: Clear
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: A
Atopy(CAD)
Haut und Fell
Atopy is a chronic allergic skin disease where a dog's immune system overreacts to common environmental substances like pollen, mold spores, and dust mites. This inappropriate immune response damages the natural protective barrier of the skin, leading to persistent inflammation and irritation. It primarily affects the skin, which is the body's largest organ system.
Haut
Epidermal dysplasia
Haut und Fell
Epidermal dysplasia, also known as Westie Armadillo Syndrome or hyperplastic dermatosis, is an inherited skin disorder where the outer layers of the skin do not develop or mature properly. This defect compromises the skin's natural protective barrier, making it highly vulnerable to secondary yeast and bacterial infections. The condition primarily affects the integumentary (skin) system, leading to chronic, severe inflammation.
Haut · Passing: CLEAR
Ichthyosis(ICT)
Haut und Fell
Ichthyosis is an inherited skin disorder where the outer layer of the skin, the epidermis, does not develop or shed properly. This defect in keratinization—the process of forming a protective outer skin barrier—leads to a buildup of dry, thick, and scaly skin. Because this barrier is compromised, the dog's body is more vulnerable to secondary infections.
Passing: CARRIER
Pulmonary stenosis(PS)
Herz
Pulmonary stenosis is a congenital heart defect characterized by a narrowing of the pulmonary valve or the outflow tract leading from the heart to the lungs. This narrowing restricts blood flow, forcing the right side of the heart to work much harder to pump blood. Over time, this constant strain can lead to thickening of the heart muscle and potential heart failure.
Passing: NORMAL
Pyruvate kinase (PK) deficiency(PKD)
Herz und Kreislauf
Pyruvate kinase (PK) deficiency is an inherited metabolic disorder affecting red blood cells, which lack a vital enzyme needed to produce energy. Without this enzyme, the red blood cells break down prematurely, leading to a severe shortage of oxygen-carrying cells, a condition known as chronic anemia. Over time, this constant cell destruction can cause secondary damage to organs like the liver and bone marrow.
DNA · Passing: CARRIER
Congenital deafness(CHSD)
Nervensystem
Congenital deafness is a hereditary hearing loss present from birth that affects the inner ear's sensory cells, preventing sound signals from reaching the brain. It is often linked to specific genetic variants, such as those associated with certain coat patterns like merle or piebald, or breed-specific conditions like Early Onset Adult Deafness (EOAD). This genetic defect causes the vital blood supply to the inner ear to fail, leading to the permanent degeneration of the hearing nerve cells.
Physisch · Passing: BILATERAL_HEARING
Globoid cell leukodystrophy (galactocerebrosidosis)(GCL)
Nervensystem
Globoid cell leukodystrophy is an inherited metabolic disorder affecting the nervous system, caused by a deficiency in an essential enzyme. This deficiency leads to the buildup of harmful substances that destroy myelin, which is the protective sheath surrounding nerve fibers in the brain and spinal cord. Without this protective covering, the nerves cannot transmit signals properly, resulting in progressive neurological decline.
DNA · Passing: CARRIER
Shaker dog syndrome(GTS)
Nervensystem
Shaker dog syndrome is an inflammatory condition affecting the cerebellum, which is the part of the brain responsible for coordinating voluntary muscle movements. This inflammation, believed to be an immune-mediated response where the body's immune system mistakenly attacks its own nervous tissue, leads to uncontrollable full-body tremors. The exact underlying cause of this brain inflammation remains unknown.
Roentgen · Passing: B
Chronic hepatitis(CH)
Stoffwechsel
Chronic hepatitis is a long-term, progressive inflammation of the liver, which is the organ responsible for filtering toxins and processing nutrients. This ongoing inflammation damages the liver tissue over time and can eventually lead to liver failure. It is often caused by genetic predispositions that lead to abnormal copper buildup in the liver, or by abnormal immune system responses.
Koerperfluessigkeiten · Passing: 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 — Ectropion / Entropion
Both parents must be CLEAR 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.
10 tests are currently mandatory under the relevant breed-club regulations. The most common are Ectropion / Entropion, Keratoconjunctivitis sicca (KCS) - "dry eye" (KCS), 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