If your yorkie has not shown these signs before and they just appeared suddenly (which sounds like what you are describing) you are right. It could be:
- an allergy to something new in the environment - possibly even a new pollen at this season. In this case he will need either a steroid or antihistamine to alleviate the sneezing
- a respiratory infection - in which case they usually get worse and start to feel bad by laying around and become inappetent. This would need antibiotics to treat.
- or it could be a foreign body in his nostril such as a grass seed or something that he sniffed up into his nose. This would need to be removed.
Your vet can probably guide you in the right direction after looking at him.
I hope this helps. Please click accept if it does. If you need more help, let me know.