What is nictitans gland prolapse?
A nictitans gland prolapse is an abnormal "flipping out" of the tear gland located behind the third eyelid (nictitans). This tear gland is responsible for one-third to one-half of the tears needed to lubricate the eye.

What causes a nictitans gland prolapse?
The exact cause of this condition is unknown. It is believed that there is a weakness of the ligament that holds the gland in place. The gland is therefore free to flip up and out of its normal position.

Are certain breeds of dogs prone to developing a nictitans gland prolapse?
Yes. The American Cocker Spaniel, English Bulldog, Lhasa Apso, and giant breeds are prone to nictitans gland prolapse, although many other breeds may be affected as well. Nictitans gland usually occurs in young dogs less than 1 year of of age.

How can I recognize that my pet has a nictitans gland prolapse? 
Most pet owners will notice a pink lump on the affected eye. Frequently, this
lump will disappear and reappear without treatment before it finally remains in the abnormal position.

What should be done? 
Untreated prolapsed glands may become inflamed, cause tearing and obstruct vision. Simple gland excision may cause dry eye, especially in breeds predisposed to dry eye such as the Cocker Spaniel, English Bulldog, and other small dog breeds. For this reason, the recommended treatment is surgical replacement of the gland into its normal position rather than excision.

Are there any complications associated with nictitans gland prolapse surgery?
Approximately 1 out of 20 dogs has recurrent gland prolapse after surgery. A repeat surgery is recommended. It is uncommon for a dog to require more than 2 surgeries for this condition. Nictitans swelling and ocular discharge is common for 5 to 7 days after surgery.

Should I breed my dog if it has had a nictitans gland prolapse? 
Currently, the American College of Veterinary Ophthalmologists and the Canine
Eye Registration Foundation (CERF) place no restriction on the breeding of dogs with nictitans gland prolapse.