Canine Bladder Infection: New Study May Change Treatment

Lab looking out in the distance

Just as some people are prone to bladder infections, so too are some dogs. It is not uncommon for women with bladder infections, but without symptoms, to go untreated. Even without antibiotics, these women often experience very good long-term outcomes. It made researchers at the University of Wisconsin wonder: would withholding treatment also produce good results for symptom-free dogs with bladder infections? Their research begins to answer that question.

The study of canine bladder infections
The study, reported in the July, 2014 Journal of the American Veterinary Medical Association looked at 101 overtly healthy (symptom-free) female dogs screened for bladder infections.

  • Nine of the 101 dogs (8.9%) had positive urine cultures.
  • Age did not appear to be a predisposing factor for bladder infections: six of the nine dogs with infection were young to middle-aged, and three were older dogs.

The nine dogs with infection were then monitored for symptoms—no antibiotics were administered—over a three-month time period. At the end of the three months, eight of the dogs were reexamined.

At this three-month visit:

  • One dog was lost to follow-up (no data was available)1.
  • Four of the dogs had negative urine cultures1.
  • Bladder infections persisted in the remaining four dogs and involved the same bacterial species originally cultured1.
  • None of the eight dogs developed any symptoms during the three-month observation period1.

Do canine bladder infections require treatment?
While I find this study interesting, I am reluctant to draw any hard and fast conclusions based on the small number of dogs evaluated and the relatively short period of time over which they were followed. The results certainly lend support to the notion that, when it comes to dogs with bladder infections and no symptoms, leaving the antibiotics on the shelf is worthy of consideration.

My own clinical experience is consistent with the results cited in this study. I often test urine as part of routine health screening, particularly in older dogs.

When I discover a bladder infection in an asymptomatic patient, before I determine whether or not to treat with antibiotics, I consider several factors including:

  • The individual’s history
  • Overall health
  • The species and behavior of the bacteria found in the urine

Here are some examples of how my decision would be made:

  • If my patient has a history of bladder stones, I will want to clear the infection with antibiotics—regardless of whether or not symptoms are present. This is because bacteria predispose dogs to the formation of bladder stones.
  • I am more inclined to forego antibiotic therapy if the urine culture grows Enteroccocus bacteria. While these bugs often cause no symptoms, they are unusually adept at developing resistance to wide assortment of antibiotics. No fun! It’s often best to let this sleeping dog lie.

Simply monitoring rather than treating dogs with asymptomatic bladder infections is certainly worthy of consideration. Such a decision warrants significant discussion between veterinarian and client. If antibiotics are withheld, careful monitoring for symptoms and urine testing are vital components of effective, ongoing care.

Questions to ask your veterinarian:

  1. Was the infection documented by a urine culture? If so, what bacteria were grown?
  2. Was antibiotic sensitivity testing performed? If so, what were the results?
  3. Do we know what caused the urinary tract infection? If so, how should that be addressed? If not, how would we look for the underlying cause?
  4. What will we do if the infection recurs?
  5. Do you feel it is necessary to give antibiotics if there are no symptoms?

Tell us below:
Would you feel comfortable withholding antibiotics to treat your dog’s bladder infection if there were no symptoms?

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.


1. Wan, SY, FA Hartmann, MK Jooss, and KR Viviano. "Prevalence and Clinical Outcome of Subclinical Bacteriuria in Female Dogs." Journal of the American Veterinary Medical Association (2014). National Center for Biotechnology Information. U.S. National Library of Medicine. Web. 05 Sept. 2014.

Reviewed on: 
Friday, September 5, 2014