puppy w/odorous green drainage from one nostril

Question
Our 15-week old Jack Russell Terrier has a green, odorous discharge from his left nostril only.  We were aware of this when we got him, and figured he had some kind of infection that can be cleared up.  He is currently on his 4th day of Amoxicillin, but no improvement.  He goes back to the vet Monday 3/7.  We are wondering since the drainage is from one nostril only could he have some kind of foreign body obstruction causing this problem instead of a URI.  How likely do you think this is, or do you have any other idea on what the problem could be?  On his vet check he was otherwise healthy & did not have a fever.
Thanks for any answers/advice you have.
Cindy (Bandit's mom)

Answer
The fact that it is only one nostril could signal nasal mass, fungal infection, or foreign body that is irritating one side or the nasal canal. However, I have not seen your puppy and I am not a vet so do not take this as a medical diagnosis. I would finish giving him the medication, and go to your scheduled vet appointment. Maybe it will be all he  needs. If not your vet will advise you on what to do. If it doesn't clear up I recommend that you talk to your veterinarian about referral to someone who can do a rhinoscopy (an endoscopic exam of the nasal passages), and possibly a set of head x-rays. But for now keep your hopes up and your vet appointment. I hope I helped some. Have a great afternoon.