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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 Chow Chow we have compiled 15 mandatory and 14 recommended health tests, drawn from breed-club regulations, the University of PEI (CIDD), and OMIA — weighted by severity and heritability.
What this grade means
With 15 mandatory health tests, the Chow Chow faces an above-average number of known health challenges. The musculoskeletal system is particularly prone to hip dysplasia (HD) and elbow dysplasia (ED), which can lead to chronic pain. Furthermore, eye conditions such as progressive retinal atrophy (PRA) must be strictly monitored through selective breeding; consequently, purchasing a puppy without comprehensive health documentation is extremely risky.
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 Chow Chow we track 15 mandatory tests plus 14 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 14 additional clinically recommended screenings that reduce risk in this breed.
In addition to mandatory tests:
Corneal dystrophy(CD)
Augen und Sehvermögen
Corneal dystrophy is an inherited eye disorder where abnormal, opaque materials like fats or calcium build up in the cornea, which is the clear outer layer of the eye. This accumulation typically affects both eyes and is non-inflammatory, meaning it does not cause immediate swelling or redness. Over time, these deposits can disrupt the smooth surface of the eye.
Augen · Passing: CLEAR
Primary Open-Angle Glaucoma(POAG)
Augen und Sehvermögen
Primary open-angle glaucoma is an inherited eye disease where the natural fluid inside the eye cannot drain properly. This fluid buildup causes a gradual increase in pressure within the eyeball, which eventually damages the optic nerve, the connection between the eye and the brain. Without management, this pressure leads to permanent blindness.
Augen · Passing: CLEAR
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
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: AFFECTED
Cervical vertebral compressive myelopathy(CVCM)
Bewegungsapparat
Cervical vertebral compressive myelopathy, commonly known as Wobbler syndrome, is a condition affecting the spine where the spinal cord in the neck becomes pinched. This compression is caused by malformed neck vertebrae or slipping discs between the bones. Over time, the constant pressure damages the nerve pathways that carry signals from the brain to the limbs.
Roentgen · Passing: A
Myotonia(MC)
Bewegungsapparat
Myotonia is an inherited muscle disorder where a dog's muscles are unable to relax normally after contracting. This is caused by a genetic defect in the electrical channels of the muscle cells, leading to constant over-excitement of the muscle tissue. Because the muscles remain tense instead of releasing, it directly impacts the dog's ability to move smoothly.
DNA · Passing: CARRIER
Color Dilution Alopecia (CDA)(CDA)
Haut und Fell
Color Dilution Alopecia is a genetic skin disorder that affects dogs with diluted coat colors, such as blue, fawn, or lilac. It is caused by an abnormal distribution of pigment within the hair shafts, which makes the hair brittle and prone to breaking. This structural weakness leads to progressive hair loss and leaves the skin more vulnerable to irritation.
Haut · Passing: CARRIER
Growth hormone-responsive dermatosis; adrenal sex hormone-responsive dermatosis
Haut und Fell
This is a hormonal skin condition affecting the endocrine system, where an imbalance in adrenal sex hormones or a lack of growth hormone leads to symmetrical hair loss. The skin's hair follicles stop producing new hair, causing them to enter a permanent resting phase. While the skin and coat are affected, the dog's internal organs and overall physical health typically remain completely normal.
Koerperfluessigkeiten
Sebaceous Adenitis(SA)
Haut und Fell
Sebaceous adenitis is an inflammatory skin disorder where the dog's immune system mistakenly attacks and destroys the sebaceous glands, which are the glands responsible for producing natural skin oils. Without these oils, the skin loses its protective moisture barrier, leading to severe dryness and damage to the hair follicles.
Passing: CARRIER
Diabetes mellitus(DM)
Hormonelles und Stoffwechsel
Diabetes mellitus is a chronic metabolic disorder affecting the endocrine system, specifically the pancreas, which fails to produce enough insulin. Insulin is a vital hormone that allows the body's cells to absorb glucose, or sugar, from the bloodstream to use as energy. Without sufficient insulin, sugar builds up in the blood while the body's cells are starved of fuel.
Koerperfluessigkeiten · Passing: CLEAR
Hypothyroidism
Hormonelles und Stoffwechsel
Hypothyroidism is an endocrine disorder where the thyroid gland, located in the neck, fails to produce enough thyroid hormones. These hormones are essential for regulating the body's metabolic rate, which is the speed at which cells convert nutrients into energy. When hormone levels are too low, the dog's entire metabolism slows down, affecting multiple organ systems.
Koerperfluessigkeiten · Passing: CARRIER
Cerebellar abiotrophy(CA)
Nervensystem
Cerebellar abiotrophy is an inherited neurological disorder affecting the brain, specifically the cerebellum, which regulates balance and movement coordination. In affected dogs, the nerve cells in this region prematurely degenerate and die off. This progressive cell loss disrupts the brain's ability to control smooth physical movements.
DNA · Passing: CARRIER
Hypomyelination(HYM)
Nervensystem
This is an inherited neurological disorder affecting the central nervous system, where the protective myelin sheath that insulates nerve fibers fails to develop properly. Without this adequate insulation, nerve signals cannot travel efficiently between the brain and the body. This disruption leads to impaired coordination and involuntary muscle movements.
Passing: CLEAR
Cerebellar hypoplasia(CH)
Nervensystem
Cerebellar hypoplasia is an inherited neurological condition where the cerebellum, the part of the brain responsible for coordinating voluntary movement, fails to develop fully. This underdevelopment is autosomal-recessive, meaning a puppy must inherit the gene from both parents to be affected. Because it only impacts physical coordination, the dog's cognitive abilities, intelligence, and awareness remain completely normal.
Roentgen · Passing: A
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 — Elbow Dysplasia
Both parents must be Grade 2 or better 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.
15 tests are currently mandatory under the relevant breed-club regulations. The most common are Cleft palate, Congenital malformations, Monorchidism. 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