So the vet came out Tuesday around 11:40 and started giving Echo an exam.
All of her vitals were normal and didn't appear to have any physical problems. The vet was a little stumped and suggested we do blood work.
Then after taking one more look under her tail to make sure there were no obvious problems Echo urinated in front of the vet. It made me happy because I'm pretty sure the vet thought I was lying about her straining. Vet ran to her truck and got a tube and was able to get a half vial of urine to test. She agreed it was definitely more milky and white than it should be.
She drew blood to test and make sure her kidneys are functioning well. She doesn't believe she has kidney or bladder stones because there was no blood to indicate one.
Tuesday afternoon I got a call from the vet that all her levels were normal. She told me to stick to the plan of 7 days on antibiotics and see how she does.
As of Wednesday night she's eating normal and acting ok. Still not done worrying. I found out today from some reputable horse people that this particular vet has had many complaints. The main vet with this clinic is amazing, but this girl seems to not be as... trustworthy. If Echo isn't feeling better or is still having problems by tomorrow night I may be looking at calling a second vet for a different opinion. Until then, she keeps getting her antibiotics and is out of work until she's better.