foxtail

Background - We are in Cali, lots of foxtails. We take Jack for daily walks. Additional complication, a couple of days back Jack jumped up on our mesh metal chair and got one of his toenails stuck in the metal mesh. My niece was watching him at the time and is not 100% it was this nail...

So I have a chihuahua-golden-lab dog, and he's around 8-9 years old. Yesterday afternoon, he started having random sneeze attacks... like he would sneeze 7x in a row and then 4x or he wouldn't sneeze for a while, and then randomly sneeze here and there. He rarely ever sneezes, so I'm taking this...