My name is ***** ***** I’ve been involved professionally with dogs in the health and behavioral fields for over 18 years. I have been breeding rottweilers for over 20 years It will be my pleasure to work with you today.
This might be ectropion but usually that is diagnosed at a young age, but can be aquired due to injury or even some medicatl conditions. Read more on this here:
Since a thyroid issue can lead to this, you will want to be sure that is checked for. In addition, in some cases of Myasthenia Gravis the first symptom noticed was droopy eyelids. You might want to read more on this here:
He may have just had a great vet visit but injury can cause this condition and if your vet wasn't looking for these conditions and there were no symptoms yet, he might not have noticed.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.