Aww, Nikko is such a cutie! I’m sorry he’s having some sneezing fits lately. Allergies or infections like kennel cough can set them off. So can being near cigarette or marijuana smoke, incense, candles, or having something small (blade of grass/bug) stuck up the nostril. There is not much you can do at home. If it’s non-stop, or happening frequently for more than 24 hours, see your vet to he’ll narrow down the causes and get recommendations for treatment. Best of luck to you and Nikko!