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Canine Bladder Infection: New Study May Change Treatment

Posted September 05, 2014 in A Vet's Life

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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

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Nancy has more than 30 years of experience in the veterinary industry and is a board-certified veterinary specialist in internal medicine as well as a valued member of IDEXX’s Pet Health Network team since 2014.

Opinions expressed are those of the writer:

The opinions and views expressed in this post are those of the author's and do not necessarily represent the beliefs, policies or positions of all veterinarians, Pet Health Network, IDEXX Laboratories, Inc. or its affiliates and partner companies.