Bladder Infections: Is Treatment Always Necessary?

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.


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 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.

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

Best wishes,

Nancy Kay, DVM

Diplomate, American College of Veterinary Internal Medicine
Author of Speaking for Spot: Be the Advocate Your Dog Needs to Live a Happy, Healthy, Longer Life
Author of Your Dog’s Best Health: A Dozen Reasonable Things to Expect From Your Vet
Recipient, Leo K. Bustad Companion Animal Veterinarian of the Year Award
Recipient, American Animal Hospital Association Animal Welfare and Humane Ethics Award
Recipient, Dog Writers Association of America Award for Best Blog
Recipient, Eukanuba Canine Health Award
Recipient, AKC Club Publication Excellence Award
Become a Fan of Speaking for Spot on Facebook

Please visit to read excerpts from Speaking for Spot and Your Dog’s Best Health.   There you will also find “Advocacy Aids”- helpful health forms you can download and use for your own dog, and a collection of published articles on advocating for your pet’s health. Speaking for Spot and Your Dog’s Best Health are available at,, local bookstores, and your favorite online book seller.

Be Sociable, Share!

4 Comments on “Bladder Infections: Is Treatment Always Necessary?

  1. What were they monitoring for though? Just the development of signs of a UTI? Never mind only a three month period, and a small number of dogs. They didn’t monitor for development of stones, or renal disease. How was the urine collected? I guess if I was thinking of not treating, I would make sure to follow up with future urine samples collected via cystocentesis and I would want to make sure the dogs had no incontinence as well.

  2. Interesting topic/question. I’d have to say it would have to depend on my particular dog’s overall situation. Perhaps there would be a time when not treating might be a better idea, perhaps treating would be the best thing to do. For me this doesn’t work as a theoretical question because I feel a number of specific criteria would need to be evaluated.

  3. Thanks again for a thoughtful post regarding not prescribing drugs w/out much consideration, first. That said, I feel that animals will heal themselves many times w/out intervention as this is what’s most natural for them to do. They let us know when it’s time to take action. It’s always so hard to allow the body to do what it’s supposed to do in this very fear based medical world and for this your spirit along w/ your medical knowledge are so much appreciated.

  4. No I would not leave it untreated if I knew my dog had a positive test for bacteria in it’s urine without clinical signs I was picking up the first time it happened in my Dalmatians – perhaps I would in my Vs..if it seemed like it repeated itself without developing into a more serious infection, then I may be tempted to leave it for a while..the thing is that in the vast majority of cases, without symptoms, the dogs would not be tested for a bacterial presence in their urine. The age of the dog and previous and concurrent health issues in the dog and the breed of the dog would also have to determine what was done and when..