Why did she get sick?

I have a Chihuahua named Daisy, who 2 months ago, was treated by a vet for an Ear Infection. She was on Panalog Cream for 2 weeks. Her infection cleared up and she was also cleared by the vet. I had to take her back to the vet again this past Monday, because her Ear Infection came back with a vengence. The vet cleaned her ears out and put some medication in them at the office. He took and Ear Culture and told me it would take 4 days, to get the results back from the vet. In the meantime, he put Daisy on an Antibiotic called Baytril Otic Ear Drops. She is supposed to get 2 drops in each ear, twice a day, until the results come back from the Ear Culture and he knows for sure where Daisy’s Ear Infections are stemming from, so he can put her on the right Antibiotic for that specific problem, to hopefully be able to get rid of her Infection and find a way to be able to stop them from coming back. He also put her on Metacam for pain and said to put 2 drops only in her food once a day, if she seems like she’s in pain and she needs it. She hasn’t needed the Metacam yet, because since he cleaned her ears out and put medication in them at the office, her ears don’t seem to be bothering her and she’s not digging at them. The redness is also not as obvious as it was when I first took her in. He told me to start the first dose of the Baytril this morning (Tuesday). This morning I gave daisy her first treatment. About 10 minutes later, she was acting a little off kilter and off balance. After a while she was fine. When I gave her the second treatment tonight, after about 10-15 minutes, she threw up 2 times and was acting very withdrawn, shaking and again off balance. I got concerned, so I called the Emergency Vet and the vet there said, that he does not think that the Baytril would have caused Daisy to throw up. He said that it’s probably because when the ear is infected, that it tends to make a dog act a little strange. He said if she throws up again to bring her in. She hasn’t thrown up again and it’s been a couple of hours. She also ate and has kept it down. She’s acting perfectly fine now! Have any of you, had to give your dog Ear Infection medication and had your dog throw up or act strange shortly after the medication was given? What do you think caused Daisy to throw up and act so strange, so soon after I gave her the ear medication? I will call my regular vet in the morning and tell him what happened, but I just wanted to see if anyone here, has ever had a reaction like this, with Ear Infection medication with their dogs! Thanks Everyone!