Patent urachus is a minor deformity in the urinary tract of a dog. It is usually not too serious, although it may cause side effects such as frequent urinary tract infections. The condition is usually corrected in young puppies, and those who undergo treatment generally fully recover and lead normal lives.
In a fetal puppy, the urachus is a tube connecting the bladder to the allantoic sac. It allows removal of urine through the umbilical cord and elimination through processing in the mother's body. When birth nears, the urethra starts to take over the job of elimination, and the urachal cord generally atrophies and closes. The process is usually complete before the birth of the puppy.
Sometimes the atrophying process is interrupted, and the urachus either never entirely closes or reopens. In patent urachus, the urachus remains entirely open, and urine may escape the body either through the urethra or through the umbilicus. Newborn puppies with this deformity may have frequent urinary tract infections, develop infections of the umbilical cord stump or develop skin rashes from the acidity in the urine.
Your vet will most likely diagnose this condition by injecting your dog with a dye and taking an X-ray. The dye will allow the vet to see the flow of fluid in your dog and find any abnormalities. Treatment of this condition is usually relatively simple. The veterinarian will surgically remove the entire urachus to correct the problem and treat any bladder infections with antibiotics. The treatment is generally effective, and the prognosis is good.
Other abnormalities exist in which the urachus may not be patent but is also not fully closed. Some dogs may have partially open urachi, forming diverticulae or small sacs. This sacs will hold urine and may cause urinary tract infections. Dogs may also have cysts of their urachi, resulting in difficulty controlling urination. These conditions are also easily treated with surgery, and the prognosis for these dogs is good.
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