Bacterial Cystitis in Dogs

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 typically smaller volumes)
  • Incontinence/accidents
  • Discomfort (evidenced by restlessness, abdominal pain, crying or licking)
  • Stiffness/reluctance to move (since some dogs develop secondary ‘flu-like’ joint aches)

How is bacterial cystitis confirmed?
As always, if you have any concerns at all about your pet’s health, see your veterinarian. After taking a thorough history and doing a complete physical examination, your veterinarian can run certain laboratory tests to confirm cystitis. If your pet is being treated for any of the predisposing conditions listed above, routine testing for a bladder infections will probably be run even without overt clinical symptoms of one.

First, a urine sample will need to be obtained; ideally the sample will be taken with a sterile needle and syringe–just like taking a blood sample. This may sound harsh, but the procedure is well tolerated by most dogs and yields a sample free of potential contamination. Catheterization by comparison can cause a bladder infection if one did not exist beforehand and simply catching a voided urine sample can include bacteria from multiple other sources on its way out.

Your veterinarian may run some quick tests in the hospital looking for things like blood, protein, pH changes and crystals; but the only real, definitive test is a bacterial culture on the urine sample. Your veterinarian can also advise you whether further tests (such as blood tests, radiographs, or ultrasounds) are needed.

Bacterial cystitis treatment
If bacteria are identified in your pet’s urine sample then an antibiotic sensitivity screening should be performed to determine the best antibiotic to use for that infection. Taking these steps in order to choose the correct antibiotic from the start can ultimately save you time and money and can save your pet unnecessary discomfort associated with further delay in clearing the infection.

The timing and number of any follow-up visits will depend on your pet’s individual situation. Your veterinarian may also recommend repeating cultures during antibiotic therapy and again even after your pet has finished the course of treatment to be absolutely sure that the infection was resolved and that it did not recur.

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.

Reviewed on: 
Monday, April 28, 2014