Toddler breath smells of urine?!

My daughter hasn't been well and we saw the doctor yday and she thinks it's viral with upper respiratory inflammation. Well recently I kept smelling urine and thought it might be wee from her potty training or something or I'm pregnancy (sadly I'm not). My husband said to smell her breath and it stinks of urine! Should I be concerned? I'm making a doctors appointment tomorrow I'm so worried. Any help or advice? She has a smaller appetite but stil eating and drinking as normal and wet nappies