My dog Nina is recovering from cruciate surgery. For the past 2 days she has not peed in the morning and holds it until about 4-5pm (~16 hours w/o urinating). Then she pees a couple of more times at night, but refuses to go in the morning, even when I stand out there for 30 minutes and try again on my lunch break from work for 30 minutes. Anybody else ever have their dogs do this? She just stopped her antibiotics this weekend so I am fairly certain it isn't a UTI, but who knows. She doesn't seem uncomfortable or painful when her belly is touched. No blood in urine and she pees all in one spot when she actually does go. I am really starting to worry because I don't want her to hurt herself by holding it for so long.