A Black Third Eyelid and Yellow Discharge From One Nostril

Many dogs have a dark-pigmented edge on the third eyelid, and in some it is mostly or fully dark, which can be normal. But a change you have just noticed, together with yellow discharge from the nostril on the same side, should be checked by a vet.

Discharge from one nostril usually means something is happening in that side of the nose, such as an infection, a tooth root infection, something stuck in the nose (like a grass seed), or less often a growth. Problems in the nose can affect the eye on the same side because the tear duct drains into the nose. A newly dark or raised third eyelid can also be a pigmented growth.

Ask your vet to examine both the eye and the nose. They may suggest checking the teeth, X-rays or a scan of the nose, or a look up the nose under sedation. Go sooner if there is bleeding from the nose, facial swelling, or sneezing that gets worse.

See eye tumors in dogs and nose problems and tumors in dogs.

This is general information, not a diagnosis. Please follow your own vet's advice.