Canine Bladder Infections Part IV: Is Treatment Always Necessary

by Nancy Kay, DVM

This is a four part article: These articles will discuss diagnostic testing and treatment.
Part I | Part II | Part III | Part IV

My recent blog posts have focused on canine bladder infections including their causes, associated symptoms, diagnosis, and treatment. The question arises, is it always necessary to treat a bladder infection, particularly if the patient has no symptoms?

Women who have bladder infections, but with no symptoms commonly go untreated, and they have good long-term outcomes. Until now, there really has been no outcome research for dogs with asymptomatic bladder infections who are left untreated with antibiotics.

A study of symptom-free bladder infections
A recent study reported in the Journal of the American Veterinary Medical Association reported on 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: six of the nine dogs with infection were young to middle-aged, and three were older dogs.

The nine dogs with infection were simply monitored for symptoms- no antibiotics administered- over a three-month time period. At the end of the three months, eight of the dogs were reexamined. One dog was lost to follow-up. At this three-month visit four of the dogs had negative urine cultures. Bladder infections persisted in the remaining four dogs and involved the same bacterial species originally cultured. None of the eight dogs developed any symptoms during the three-month observation period.

Conclusions
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, and the species and behavior of the bacteria found in the urine. Here are some examples of how my decision-making would be swayed.

  • 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 to the formation of bladder stones.
  • I am more inclined to forego antibiotic therapy if the urine culture grows Enteroccocusbacteria. 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.

    Would you feel comfortable withholding antibiotics to treat your dog’s bladder infection if there were no symptoms? Has your dog ever had a bladder infection? If so, what symptoms did you observe?

    CREDIT:
    Dr. Nancy Kay, DVM Diplomate, American College of Veterinary Internal Medicine.
    Recipient, American Animal Hospital Association 2009 Animal Welfare and Humane Ethics Award Recipient, 2009 Dog Writers Association of America Award for Best Blog Recipient, 2009 Eukanuba Canine Health Award

    Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
    Website: http://speakingforspot.com
    Spot’s Blog: "http://www.speakingforspot.com/blog
    Email: dr.kay@speakingforspot.com
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