How many eyelids does a dog have?

Accessory structures. The eye has many accessory structures present to ensure that it is protected and clean. These structures include the eyelids, eyelashes, lacrimal (tear) glands, and nictitating membrane. Most animals have three eyelids: the upper lid, lower lid, and nictitating membrane (third eyelid). read more

There's nothing abnormal about a dog having a third eyelid because they all have one. The third eyelid even has its own name: the nictitating membrane, or haw. These membranes are the same in different breeds and sizes of dogs, although the pigmentation of the third eyelid may vary from breed to breed. read more

There is a tear gland around the cartilage of the third eyelid that produces about 1/3 of tears for the eye. In a dog with cherry eye, the fibrous attachments of the gland to of the third eyelid are weak or strained. read more