Dog keeps sneezing and shaking his head?

I just took my dog to the vet for his one year check up a few days ago, and he is completely up to date on all of his shots, but he keeps sneezing and shaking his head. Should I be worried, or just give him some Benadryl and see if it gets better? He is a one year old cairn terrier.

It's possible he has something foreign in his nasal passages - a burr, a bug, or small piece of debris. I wouldn't give him anything until he can be seen by a vet. Shaking his head along with the sneezing, sounds as though he's trying to dislodge something.If this is sneezing is going on continually, I would try to get him into a vet right away since whatever is in there could be causing some severe problems. At least call your vet - they have after hour emergency numbers. Let him know what's going on and he can recommend something. But, please don't medicate him! If there is something lodged inside his nostril or sinuses, it needs to come out.I