Hello, I am Dr. Peter a licensed Veterinarian. I would like to help. I need to ask you a few questions to be well informed and give you the best advise. There is no additional charge for information request.
1- Is he coughing?
2- How long has this been going?
3- Any pre existing medical conditions?
He has been sneezing for a few days and i just noticed the mucus from his nose.
He is not coughing at all.
He sometimes shakes his head.
He has no other health issues.
No, mostly it is clear, but when he wakes up in the morning there is some green crusty stuff. He is licking his nose a lot.
None of what I have seen is yellow at all.
The green color is consistent with a bacterial infection, your dog does not have a cold but rather a sinus/nostril infection. The best option for him is to start him on oral antibiotics. In the meantime, what you can do is open the hot water in the bathroom and allow him to breath the steam for 5-10 minutes 2-3 times a day. Follow up with your veterinarian.
Hope the above helps, if you have additional questions I will be glad to answer them.