6 weeks ago, Zoe (6 year old lab/border collie mix) woke us up in the middle of the night panting- which means she NEEDS to go out! Took her out and she peed about 10 times. Took her to the vet next day and sent urine to the lab- she had ecoli. Put her on an antiobotic (note, cannot use Cipro as she had an allergic reaction in the past). Two weeks on this, she seemed fine, no recurrance of the night-time urgency. A week after we finished the antibiotics, took another urine sample to be sure ecoli was gone--- it was not. Put her on a different antiotic for two weeks...during which she was acting totally normal. Finished second round a week ago, and....last night up at midnight having to go out and peed 6 times urgently. So...got another urine sample from her this morning and am dropping it off at the vet. I don't know why this is so insidious or how she even got it. We have been feeding her Wellness brand food- both dry and wet for over a year and she loves it. She does not eat dog poop, but we do live near a lagoon that she splashes around in-- some think it's polluted, but she's been swimming in it for 6 years now. Thoughts???