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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 Hairless Chihuahua we have compiled 3 mandatory and 3 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 Hairless Chihuahua receives a D grade because the genetically linked hairlessness (ectodermal dysplasia) is almost always accompanied by severe dental malformations and extremely sensitive skin. Furthermore, the breed is prone to typical toy breed issues such as patellar luxation and tracheal collapse. Since there are no mandatory health tests required for this specific variant, purchasing one involves a significant health risk.
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 Hairless Chihuahua we track 3 mandatory tests plus 3 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 3 additional clinically recommended screenings that reduce risk in this breed.
In addition to mandatory tests:
Tracheal collapse(TC)
Atmung
Tracheal collapse is a progressive respiratory condition where the C-shaped cartilage rings that keep the windpipe (trachea) open begin to weaken and flatten. As these supportive rings lose their rigidity, the airway narrows, making it difficult for air to pass smoothly into the lungs. This mechanical failure of the respiratory tract leads to chronic irritation and breathing difficulties.
Roentgen · Passing: A
Myxomatous mitral valve disease(MMVD)
Herz und Kreislauf
Myxomatous valve degeneration is a chronic heart disease where the heart valves, most commonly the mitral valve, gradually thicken and lose their normal shape. This structural change prevents the valves from closing tightly, causing blood to leak backward through the heart chambers. Over time, this backflow forces the heart to work much harder, eventually leading to congestive heart failure.
Ultraschall · Passing: NORMAL
Hydrocephalus
Nervensystem
Hydrocephalus is a neurological condition affecting the brain and nervous system, commonly referred to as water on the brain. It occurs when cerebrospinal fluid, the natural protective liquid surrounding the brain, builds up abnormally inside the brain's cavities, known as ventricles. This accumulation creates harmful pressure on the surrounding brain tissue, which can impair normal brain function.
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 — Progressive Retinal Atrophy (PRA)
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.
3 tests are currently mandatory under the relevant breed-club regulations. The most common are Progressive Retinal Atrophy (PRA) (PRA), Patellar Luxation (PL), Hairlessness. 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