The dog’s third eyelid may be slightly prolapsed if it heals on its own, but in most cases it cannot heal on its own. Therefore, if your dog has a third eyelid, it must be sent to the pet hospital for examination to confirm whether surgery is needed. Remove it, otherwise it will seriously affect the dog's vision, and may also cause bleeding at the corners of the eyes, inflammation of the eyes, etc.
Tip:
The third eyelid in dogs is hereditary to a certain extent, so you should pay more attention to avoid passing it on to the next generation.