Animal Update: What Causes 'Cherry Eye' In Dogs?

(CBS SF) - Unlike humans, dogs have a third eyelid which provides protection for the eye. A special tear gland is located beneath the inner corner of each eye, and it's connected to the third eyelid. Sometimes, the tear gland pops out of its normal position, protruding from behind the eyelid and it looks like a reddish mass bulging out of the corner of the eye. The official term for this: Cherry Eye in dogs.

What causes it?

"It seems to be a combination of structural abnormality and unusual inflammation," said Dr. Jack Aldridge, Director of Veterinary Services at the SF SPCA. "Sometimes partially due to a defect in the cartilage that helps form the third eyelid and holds it in place."

"Now, any dog, male or female, can develop Cherry Eye in one or both eyes but it's usually seen in pups or other young dogs," he continued.

"Cherry Eye is almost unheard of in cats," Aldridge stressed.

He added that the condition itself isn't painful but when a prolapsed gland is exposed, it can become swollen or inflamed, otherwise damaged, or an ulcer can form on the surface on the eye, making surgery the only way to correct the problem.

KCBS' Jeff Bell Reports:

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