Primary Lens Luxation (PLL) in Chinese Crested Dogs
Primary lens luxation (PLL) is an inherited eye disease in which the lens detaches from its normal position because the small fibers holding it in place weaken. The condition is painful, can lead to glaucoma and blindness, and affects several terrier breeds and related breeds, including the Chinese Crested.
What causes PLL?
PLL is caused by a mutation in the ADAMTS17 gene. Inheritance is autosomal recessive, meaning a dog must inherit the mutation from both parents to develop the disease. Dogs with only one copy (carriers) do not normally develop the disease themselves but can pass the mutation on to offspring.
Important health information
Symptoms of PLL — sudden redness, cloudiness, or pain in the eye — require urgent veterinary care. Untreated glaucoma resulting from PLL can cause permanent blindness within hours.
How does DNA testing work?
A simple DNA test (cheek swab or blood sample) can determine whether a dog is clear, a carrier, or affected by the PLL mutation, long before symptoms would appear. Reputable breeders test all breeding stock and can show documented, laboratory-issued results on request.
What does this mean for breeding?
Responsible breeding means never pairing two carriers or two affected dogs. A reputable breeder can always show documented PLL results for the parent dogs. Read our genetics series to understand how recessive traits like this are inherited and calculated.
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See also progressive retinal atrophy (PRA-rcd3), another inherited eye disease in the breed, and the full health overview.