Puppy has chronic uti (urinary tract infection), need special vet.?

Hi, my 7 month old goldendoodle puppy has been getting urinary tract infections for the past few months. We have tried several different antibiotics(short term cures), and even went as far as having exploratory surgery done, where they found nothing wrong. Finally, the vet told us that he thinks there is tiny hole in her urinary tract that is linking with her anus, causing infection. In humans, urologists solve this by using a dye in which shows up on x-rays, locating this tiny hole. The vet said the chances of finding a vet that is capable of performing this procedure is extremely slim. If you are a vet, or know a vet capable of this type of procedure, please, let me know. Also, if you have any suggestions on what to try, I would also greatly appreciate it. Thank you.