Persistent Papillary Membranes in Dogs: Causes & Care

Persistent Papillary Membranes (PPM) are delicate strands of tissue found in some dogs’ eyes. These are remnants of vital blood vessels that nourished the puppy's lens while in the womb. Normally, these strands regress and vanish by four to five weeks of age. However, in some dogs, they persist, hence the name.

PPM is an inherited condition, passed from parent dogs to their puppies, although the exact genetic mechanism remains unclear. Often, dogs with these tissue remnants experience no issues. But, the impact on vision depends greatly on the location and extent of the membranes within the eye.

Breeds Most Affected by Persistent Papillary Membranes

Certain breeds show a higher predisposition to PPM, including:

• Basenji puppies
• Pembroke Welsh Corgi puppies
• Cardigan Welsh Corgi puppies
• Mastiff puppies
• Chow Chow puppies
• Yorkshire Terrier puppies

Notably, Basenjis often display a form of PPM that forms a bridge to the cornea, causing clouding that can significantly affect vision. This breed may also experience optic nerve coloboma, contributing to blindness in rare cases.

How Vets Diagnose PPM

Persistent Papillary Membranes are usually diagnosed in young dogs when white spots or strands are visible in their eyes. A veterinarian conducts a comprehensive eye exam using an ophthalmoscope, considering the dog's full medical history. This exam helps pinpoint the presence and position of membranes—whether on the cornea, lens, or other parts—and evaluates any potential impact on eyesight.

Managing and Treating PPM

Currently, there is no direct cure for PPM itself. Yet, treatment may include specific eye drops recommended by a vet to support eye comfort. Should cataracts develop as a complication, surgical removal might be advised to improve vision. Fortunately, PPM-related cataracts typically do not worsen over time, as PPM is not a progressive condition.

Promoting Responsible Breeding to Reduce PPM

Responsible breeding plays a crucial role in reducing PPM incidence. Breeders should avoid using dogs diagnosed with PPM in their programmes, regardless of breed, to prevent passing on the condition.

For example, in breeds like the Basenji, breeder vigilance is imperative. Puppies should be screened by a veterinary ophthalmologist around nine weeks old. The OFA Eye Certification Registry offers a resource to check a dog's eye health status, though it cannot guarantee offspring will be entirely free of PPM.

Living Joyfully with a Dog Affected by PPM

Most dogs with PPM lead full and active lives. The condition often has little or no effect on their quality of life since it is non-progressive. In many puppies, the membrane strands naturally reabsorb and disappear as they mature.

Severe cases are uncommon; however, dogs are remarkably adaptable and can thrive even with some visual impairment caused by PPM. Regular veterinary check-ups help ensure these pets remain happy and healthy.