Persistent Pupillary Membrane, or PPM is one of the more unusual eye conditions that dogs may experience. The condition results in strands of membranes or blood vessels which supply nutrients to the developing eye being left over after birth. In most cases, these vessels will deteriorate and disappear shortly after birth. When these membranes do not disappear, it is known as PPM.

Persistent Pupillary Membrane may impair the dog’s vision depending on the location of the strands. They may cross from the iris to the cornea where they can cause cloudiness in the cornea or cross from the iris to the lens of the eye, potentially causing early-onset cataracts or can clump together as sheets of fibrous tissue within the anterior chamber of the eyeball.

PPM can be found in many breeds of dogs including the Alaskan Malamute, Australian Shepherd, Beagle, Belgian Sheepdog, Cocker Spaniel, Doberman Pinscher, Old English Sheepdog and all types of Collies, Poodles, Retrievers, Setters and Terriers.

Diagnosis is often done by a vet through use of an opthalmoscope, but in some cases, can be easily noticed as a membrane in the dog's eye in the form of small white spots. Persistent Pupillary membrane is in itself untreatable, but in most cases this condition does not affect the dogs vision. However, if there is swelling or "bluing" of the cornea, anti-inflammatory eye drops may be prescribed to reduce the swelling. If there are extensive cataracts, surgery may be performed as well.