The eye relies on a delicate balance between the production and drainage of a fluid called aqueous humor, which helps maintain normal eye shape and function. In dogs affected by Primary Open Angle Glaucoma, the drainage system within the eye (specifically the iridocorneal angle) becomes dysfunctional over time. This causes fluid to build up, increasing intraocular pressure. Unlike secondary glaucoma, POAG occurs without an obvious underlying injury or disease, making it more difficult to detect in its early stages.
Clinical signs of POAG-2 often develop gradually and may initially go unnoticed. Early symptoms can include mild eye discomfort, redness, excessive tearing, and intermittent squinting. As pressure within the eye increases, affected dogs may experience more severe signs such as a cloudy or bluish appearance of the cornea, dilated pupils, vision loss, and behavioral changes such as bumping into objects or reluctance to move in unfamiliar environments. In advanced stages, the eye may become enlarged (a condition known as buphthalmos) and complete blindness can occur.
The POAG-2 DNA Health Test is designed to identify the specific genetic mutation associated with this form of Primary Open Angle Glaucoma. Testing is simple, safe, and non-invasive, typically requiring either a cheek swab or blood sample. The collected sample is analyzed in a specialized laboratory to determine the dog’s genetic status. Because DNA does not change over time, testing can be performed at any age, including before clinical symptoms develop.
Results are generally reported in one of three categories:
- Clear (Normal): The dog does not carry the POAG-2 mutation and is not expected to develop this form of glaucoma or pass it to offspring.
- Carrier: The dog carries one copy of the mutation but may not show clinical signs. However, it can pass the mutation to future generations.
- Affected/At Risk: The dog carries two copies of the mutation and has a significantly increased likelihood of developing Primary Open Angle Glaucoma (POAG-2).
Genetic testing for POAG-2 provides valuable insight for breeders, veterinarians, and dog owners. Breeders can use test results to avoid high-risk matings and reduce the prevalence of the disease in future generations while maintaining healthy genetic diversity. Eliminating carrier-to-carrier breeding significantly reduces the risk of producing affected puppies.
For dog owners, understanding a dog’s genetic status enables proactive eye health monitoring. Dogs identified as at risk should undergo regular ophthalmic examinations to detect early changes in intraocular pressure. While there is currently no cure for glaucoma-related optic nerve damage, early detection and veterinary intervention—such as pressure-lowering medications or surgical management—can help slow progression and preserve vision for as long as possible.
The Primary Open Angle Glaucoma (POAG-2) Health Test is a reliable genetic screening tool that supports responsible breeding practices, promotes canine ocular health, and helps reduce the impact of this inherited cause of blindness in future generations.
