PLL is most commonly observed in dogs 3 to 8 years of age. Subluxation, where the lens is partly detached, commonly occurs before complete luxation. An anterior lens luxation is particularly serious and manifests as squinting, redness, and watering of the eyes, requiring immediate veterinary care.

Untreated, PLL results in glaucoma, corneal opacities, corneal edema, and blindness. The second lens tends to become displaced within weeks or months of the first luxation and therefore should be carefully monitored.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to develop. Carriers with one copy of this disease mutation are at a slightly increased risk of showing signs of this disease. For breeds where the disease mutation is at high frequency in the population, use of carriers for breeding may be needed to avoid loss of genetic diversity within the breed. Breeding a carrier dog with one copy of the PLL mutation with with a clear dog with no copies of the PLL mutation, will produce a litter with about half clear puppies and about half carrier puppies, with a low risk of developing clinical signs. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Please note: It is possible that disease signs similar to the ones caused by the PLL mutation could develop due to a different genetic or clinical cause.