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Bacterial Cystitis in Dogs

Posted April 28, 2014 in Dog Diseases & Conditions A-Z

Cystitis is, by definition, any inflammation of the bladder wall; the usual cause for such inflammation in dogs is a bacterial infection. 

How do dogs get bacterial cystitis?
The urinary bladder is an internal structure and, under normal conditions, a sterile environment. So how do bacteria find their way in there? It’s possible for bacteria to “descend” into the bladder through blood circulation or from the kidneys where urine is produced before being stored in the bladder. More commonly though, bacteria will “ascend” into the bladder via the urethra from outside the body or from other locations inside such as the prostate gland in males or the vagina in females.

With ascending infections, the bacteria are “swimming upstream.” They are going against the flow of urine. Surprisingly, while voiding urine can open up an entryway for bacteria, it’s also one of the key defenses the body has against the movement of ascending bacteria. That is why simply drinking more and urinating more can aid in preventing bladder infections.

Can bacterial cystitis be caused by a larger problem?
With descending bacterial cystitis, a significant infection first exists in some other location or organ system. Those bacteria get into the blood circulation. Then, when that blood flows through the kidneys, the bacteria colonize the kidneys and work their way down to the bladder with the normal flow of urine.

In addition, certain underlying, medical conditions can predispose the body to infections in general and thus to bladder infections specifically. For instance, Diabetes mellitus, Hyperadrenocorticism (Cushing’s Disease) or the administration of long-term steroids for other medical problems can predispose your pet to bladder infections.

Finally, physical abnormalities like bladder stones, polyps or tumors can irritate the bladder lining—making it more susceptible to infection—and can also serve as protected places for bacteria to congregate and to multiply.

What are the symptoms of a bladder infection?
If you have ever had a bladder infection, you know how uncomfortable it can be. Unfortunately, sometimes your pet won’t show symptoms whatsoever. In this case, you may only realize the infection exists if your veterinarian is doing routine screening tests or running tests for some other unrelated complaint.
If your pet does show signs associated with a bacterial cystitis those symptoms could include:

  • Hematuria (blood in the urine especially at the end of voiding)
  • Stranguria (straining and/or discomfort on urination)
  • Pollakiuria (increased frequency of urination and

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Mike has more than 35 years of experience in companion animal veterinary practice and is a valued member of IDEXX’s Pet Health Network team since 2013.