Dog’s Urinary Tract Infection Needs Definitive Diagnosis

Q. My 7-year-old male Pug gets frequent urinary tract infections: one every few months. Antibiotics clear it up, but in two or three months the infection is back. An X-ray has shown nothing. I know the next step is to culture the urine and have an ultrasound of the bladder, all very expensive. I’ve heard that vitamin C may be the answer to his problem. What is your advice?

A. Male dogs should not be getting frequent urinary tract infections; in fact, it is very rare for a male dog to get a urinary tract infection at all. This is because the urethra leading from the bladder to the opening in the skin is much longer than it is in females, making it less likely that bacteria can ascend the urethra into the bladder.
 
Often, there is some anatomical problem that can lead to a urinary tract infection in male dogs. Sometimes there is a problem with fecal contamination that can get in the urethral opening, causing an infection.
 
Bladder stones can cause urinary tract infections, but it sounds like an X-ray ruled that out. A tumor in the bladder is definitely worrisome, and the only way to definitively diagnose it is through ultrasound.
 
Occasionally urinary tract infections are caused by bacteria spread from other parts of the body through the bloodstream. They eventually get into the kidney, causing signs similar to, but more severe than, a bladder infection. Getting a culture of the urine may be able to help you identify the infection’s source.
 
Sometimes dogs with low thyroid levels (hypothyroidism) have compromised immune systems, leading to frequent infections. You may want to ask your veterinarian about this possibility.
 
Vitamin C or cranberry juice may help prevent urinary tract infections, and will do no harm in modest amounts. Most likely, however, the problem will persist.
 
It may cost you less in the long run to have the diagnostic testing done to identify the source of the problem, rather than continually treat recurring urinary tract infections.