Straining to urinate.

I have an 8 year old yellow lab named Chloie. She was diagnosed with hypothyroidism about 1.5 years ago and has since been taking Soloxine. She has lost a lot of weight and her energy levels are back to where they were when she was young. However, she is now straining to urinate and has been having accidents inside. I took her to the vet last month (as soon as we noticed it) and she diagnosed with a UTI and given an antibiotic, which almost immediately cleared her symptoms. The vet mentioned that her urine was a bit dilute so at that same time I had a full blood panel done on her and the vet reported that all of her levels were normal.

She was great for the entire time she took her antibiotic. She has been off it for exactly one week and she is now straining and having accidents again. I took a urine sample to my vet this morning and she said there were no abnormalities and that no infection seemed to be present. She did mention that the urine was slightly dilute, but it could be because it was her first urine of the day. She suggested we have an ultrasound of her bladder to make sure there aren't any issues there. However, they only have a person come in once a month to do their ultrasounds, and he won't be there until the 19th. I made the appointment, but I really don't want to leave her in limbo for that long, she clearly isn't comfortable.

Besides her treated hypothyroidism, she gets ear infections pretty regularly. She also has a strange growth (looks kind of like cauliflower) on the outside right around her urethra and she licks the area very often. I have had it looked at several times by the vet and she says she's never seen anything like it, but it doesn't look like anything to be concerned about. Honestly it drives me a little nuts that no one can tell me what it is. She drinks quite a bit, I'm not sure if I would call it excessive, but she is at her bowl often.

I really like my veterinarian, but Chloie is a member of our family and it's important to me that she be taken care of. I'm nervous that she could have diabetes or something that we need to address quickly, but at the same time I think this would have shown up in the blood work she just had done. I don't want to be one of those pushy pet owners that tries to tell the vet what the problem is, but I am concerned!

I'm looking for other ideas. Should I take her to a different vet? Can it wait until the 19th? I lost a dog to bone cancer a year ago and I refuse to have anything happen to my girl because we didn't act quickly enough! Any advice is appreciated.

Thank you for your thoughtful response.

After I sent my message I realized I may have left out an important detail. For the last 2 weeks my sister in law (and her dog and 2 month old baby) have been staying at our house. Last evening I took Chloie to a different area in the lawn and she didn't appear to strain at all. When I noticed her behavior on Wednesday morning I took her to her usual place, where the other dog has been going to the bathroom. I'm wondering if what I was interpreting as straining (squatting multiple times) is just her trying to cover the other dog's scent (they are both female labs)?

She is not acting sick in any way, her appetite and energy level are great. But I still have concerns about her urinating in the house. We picked up her water bowl at 9:00 last night (which we have never done before) and she obsessed over it until we had to get up at 4:00 am and let her have a drink. She's always been a very sensitive dog, I just don't want to assume it's stress related if there truly is something wrong.

I appreciate your advice. I will most likely request a urine culture or x-ray if she appears to be uncomfortable. I have made it clear to my vet that my #1 priority is keeping Chloie healthy and not to worry about "saving me money", so I hope that she would suggest any test that she thought would shed some light.

Thanks again for your time!

Chrissi