He is otherwise a very happy and healthy puppy. Do you have any idea what might be causing these sniffles and what I could do about them. Golden Retrievers are great dogs. But one thing this breed has is a high prevalence of allergies. Some are severe, some are quite mild.
Sniffles can be a symptom of an allergy.
My guess is that your dog might be allergic to something. If this sniffling is mild, I would suggest that you do nothing about it. If the sniffling becomes a concern, you might ask your veterinarian for medication to control this. Usually the medication is an antihistamine. Since that time we have been faithfully applying the prescribed steroidal eyedrops.