Urinary Tract Infections (UTIs) in Dogs

My dog suddenly started asking to go outside very frequently. When I took her out, she squatted to urinate multiple times, like a male dog who is marking his territory. On walks, she did the same thing. It seemed like she couldn’t possibly have any urine left in her bladder after the first few times. Finally, she urinated in the house and I could see a red tint. It looked like blood, so I took her to her veterinarian. A sample of urine revealed a bladder infection. How did this happen?

Urinary tract infections (UTIs) are fairly common in dogs. The scenario described above is often what leads to investigation and diagnosis by the veterinarian. Dogs with UTIs generally attempt to urinate very frequently whenever they go outside, they may strain to urinate, they may cry out or whine when urinating if it is painful, and there may be blood visible in their urine. A break in housetraining is a red flag that something is wrong in the bladder. Finally, dripping urine or frequent licking of the genitals may also signal that a UTI is present.

Generally, a UTI occurs when bacteria ascend up the urethra and into the bladder. Urine in the bladder is supposed to be sterile, but once bacteria find their way there, they can grow and reproduce, causing the UTI. Additionally, some dogs will develop bladder stones in conjunction with their UTI, which opens the door for additional health issues.

Why are microscopes used in the identification of a UTI?

The microscope can reveal so much important information about the urine when a UTI is suspected. Once parameters like urine-specific gravity (concentration), pH (acid-base balance), ketones, glucose (sugar in the urine), bilirubin (a breakdown product of blood), blood, and protein are measured, the urine specimen is placed into a centrifuge and spun for a specific period of time at a specific number of revolutions per minute.  This will allow cells and other debris to accumulate at the bottom of the tube.  That debris can then be evaluated under magnification, and this examination can reveal the presence of red blood cells, white blood cells, bacteria, and crystals. What is seen under the microscope’s magnification can lead to the next steps of assessing the dog’s urinary tract disease. For instance, if there are crystals in the urine, your veterinarian may recommend X-rays of the abdomen in order to look for bladder stones.

My veterinarian sent a sample of urine to a laboratory for what she called a “culture and sensitivity” test.  What is this and why did she send the urine away?

All urinary tract infections are NOT created equal!  Even though the most common organism to cause UTIs in dogs is Escherichia coli, there are several other organisms that may be involved.  The only way to identify what the specific bacteria is to grow it in a laboratory and test the bacteria against various tiny samples of commonly used antibiotics. Only then can we be certain we have made the best choice for treatment.

Often, a veterinarian will prescribe an antibiotic that is among the most commonly used for treating UTIs in order to try to provide immediate relief to the dog.  Once the culture and sensitivity results are received, an appropriate antibiotic will be prescribed. After the course of antibiotics is given, it is important to recheck the urinalysis to confirm that the infection is resolved. If it is not, then it will be important to investigate additional issues that may contribute to a persistent UTI.

Are some dogs predisposed to UTIs?

Older female dogs and dogs with diabetes mellitus (“sugar” diabetes) more commonly develop UTIs than the general population. Dogs who have bladder stones are prone to recurrent UTIs, pointing out the importance of getting a complete diagnosis whenever there is evidence of disease in the urinary tract. Bladder stones must be removed or dissolved in order to restore bladder health.

I noticed a change in my dog’s urination habits, and I saw blood in her urine, but are there other ways to tell that a dog has a UTI?

There are several important signs that something could be wrong with a dog’s urinary tract, including the possibility of a UTI.  These signs include:

• Passing small amounts of urine frequently
• Straining to urinate
• Blood in the urine
• Dribbling urine or lack of urinary control
• Crying out or whining while urinating
• Urinating inappropriately – – e.g., in the house
• Licking the genitals
• Strong urine odor

What can I do to prevent a UTI from occurring in the future?

Your veterinarian will let you know if there is anything that can be done to prevent your dog’s UTI from recurring. There is evidence to suggest that in the case of an E. coli UTI, a formulation of cranberry concentrate may inhibit the bacteria from attaching to the lining of the bladder, thus inhibiting a UTI. It may also be recommended to alter the pH of the urine in order to inhibit a recurrence. It’s best to discuss UTI prevention with your veterinarian in order to put into place strategies that have been demonstrated to be effective.