Poppy X Montana Puppies, 8 weeks old
Persistent Pupillary Membrane
PPMs are the remains of a fetal structure called the Pupillary membrane. The membrane covers the pupil before an animal is born and is part of the blood supply to the developing lens. Normally the pupillary membrane completely absorbs before birth in foals and calves but is partially present and continues to disappear in neonatal dogs. Absorption may not be complete in puppies when the eyes first open and small strands or a web-like structure may be seen across the pupil. These strands normally disappear by 4 to 6 weeks of age. In some dogs these strands do not disappear and become PPMs.
In general, iris to iris PPMs (The strand is attached to only iridal tissue, not touching the lens or cornea), cause no problems. They may be single strands or a forked structure. These PPMs may break and become less prominent as the puppy gets older, or seem to completely disappear.
