Nictitans prolapse (cherry eye)
The gland known as the nictating membrane or third eyelid may prolapse, or in other words, fall out from its normal position. After slipping from its regular position, it appears as a cherry red lump in corner of the eye facing the nose.
The lump appears distinctly and is usually the size of a pea or small bean. The color is dark pink or red. The condition may affect both eyes at the same time. If the prolapse is not treated or is allowed to resolve by itself, the eye becomes chronically irritated. Excessive watering and conjunctivitis may occur as a result. Cherry eye (nicitans prolapse) is more commonly seen in younger dogs and puppies. Spontaneous reposition is possible.
Inflammation can cause the gland known as the nictating membrane to swell up. Thus exposed, the tissue becomes further irritated and cannot slide back into place. A genetic defect may cause the ligament that attaches the gland to become loose, and act as predisposition for a prolapse.
If the condition does not resolve by itself, minor surgery is necessary in order to slide the gland back into position. Through a small incision, the lump is inverted into the nicitans where the inflamed tissue is allowed to settle and thus eliminate any problematic swelling.
By gentle massaging the eye, the gland may slide back into place under the third eyelid. If that is not possible, or if the prolapse reoccurs, you should consult a veterinarian.