Chattering Teeth

Khan was taken to the vet for a suspected UTI on Wednesday. He was licking
himself a lot, asking to go out more frequently than he usually does, and I
noticed that he was dribbling a little urine if say, I'm brushing him in
that area (and he wants to clean up, which might explain the licking). We
did urinalisys, and since he seemed a little tender in that area, the vet
did a prostate exam to rule that out as the problem. The urinalysis
revealsed that the specific gravity was off, the pH too high, but no RBCs,
WBCs or crystals. The urine was dilute (not an overnight catch, more like 4
hours after his prior trip outside), and the vet did the culture. The
results (as of this morning) may indicate that there is nothing growing in
there except possibly some contaminants.

Anyhow, given his discomfort, I opted to get him started on a broad spectrum
antibiotic, instead of waiting 2 more days. He was given Zeniquin, 100
mg/day (given once a day). I noticed on Wednesday night, about 4 hours
after he was given his meds, that he seemed to have chattering teeth. Like
some dogs do when they're excited, and this was definitely not in his
control. It went on for a few more times, but then he was fine for the rest
of the day. I called the vet first thing in the morning, and they said to
give him his next dose, but to call back if it recurred. Well, it did. We
noticed the same thing this morning (he hasn't done it since). Called the
vet and they adviced that we discontinue, and depending on the urine culture
results, we may not need to substitute another antibiotic.

So, anyone have any experience with similar reactivity in dogs to
antibiotics? I've never heard of anything like this. Could it be
coincidence? If so, what else could be causing it? And if this is not UTI,
what could be causing his licking/more frequent urination? The
licking/urination frequency appear to have gone down considerably in the
last day or so. He may be drinking more water than usual, and his blood has
been sent to MSU to re-test his thyroid levels (he is being treated for
hypothyroidism).

Suja