Humphies comments, with which I agree, I wanted to mention that the majority of urinary tract infections in dogs
are due to gram negative bacteria which respond best in
general to antibiotics specifically geared to kill gram negative bacteria.
Baytril and Orbax are both the same antibiotic. The difference is that Baytril is given twice daily and Orbax is given once daily. Both are specific for gram negative bacteria and in most cases are effective to clear up urinary tract infections.