How is urethral incontinence diagnosed?
Urethral incontinence is diagnosed based on clinical signs, medical history, and blood and urine tests. Bladder radiographs (X-rays) and ultrasonography are often performed to search for bladder stones or other abnormalities affecting urine storage and outflow. ( via Wikimedia Commons / Joel Mills (CC BY-SA 3.0.)
Neurological tests such as examination of the anal and tail tone, perineal sensation, and various spinal reflexes will be performed if a neurological disorder is suspected.
Urethral catheterization may be required if urine retention is observed. This determines if there is an obstruction or other urethral abnormality present.
Cystoscopy may allow your veterinarian to see an abnormality within the bladder or urethra. In certain cases, specialized testing such as measuring the pressure within the bladder is performed.
Treatment is based on your pets specific diagnosis. Medications that increase urethral sphincter tone such as phenylpropanolamine (PPA) or imipramine, or hormone replacements such as estrogen or diethylstilbestrol (DES) are commonly used alone and in combination. Many dogs that respond poorly to PPA alone will benefit from a combination of PPA and DES. Approximately 70% of all cases respond well to medical therapy alone. GnRH analogs may be considered in severe or refractory (failure to respond) cases. With long-term usage, the patients blood and urine should be periodically tested to ensure that there are no untoward side effects. Your veterinarian will prescribe the best treatment for your pets individual needs.
New research has focused on collagen injections to improve urethral closure. This surgical solution holds promise and should be discussed with your veterinarian to determine if any of the surgical specialists in your area are performing this procedure.
A: We suspect your dog needs a workup that includes diagnostic imaging with an ultrasound. Young dogs such as yours do get urethral sphincter incompetence after spaying because once their ovaries are removed, they stop producing almost all estrogen, which gives the sphincter its tone. But the condition is much more common among older dogs. “The more typical scenario is that it starts when the dog is seven, eight, or nine years of age,” says Linda Ross, DVM, a urinary specialist at the Cummings School. In addition, Dr. Ross says, the dribbling associated with sphincter incompetence tends to be intermittent, involving only small amounts of urine, whereas you’re describing more consistent and copious urinary deposits. (It’s worse when the dog has been sleeping because the sphincter muscle relaxes even more when a dog is in repose.)
The first step is basic lab work — urinalysis and a urine culture to check for infection. Sometimes an infection by itself can contribute to incontinence, but also, if there’s a problem with the sphincter, bacteria can make their way up the urethra because the sphincter isn’t closing tightly enough.
If we can’t make a diagnosis on ultrasound, says Dr. Ross, we move on to the next diagnostic step — cystoscopy. The dog is put under general anesthesia, and we look at the openings of the two ureters (one attached to each kidney) directly with a scope. Sometimes, if we see an ectopic ureter, we can make the correction during the procedure. In other cases, where we can’t locate the openings of the ureters, we may end up having to do more imaging with a CT scan and going in surgically.
Q: We adopted an adorable 6-month-old puppy a couple of months ago, and from the day we got her, she has been dribbling urine. After lying down and relaxing or snoozing, she leaves wet spots wherever she has been – on her own dog bed, on the couch, on rugs – everywhere. It is not a small amount. Sometimes the stain covers an area wider than a sheet of paper, and if we pick her up supporting her bottom, our hands get wet. Our veterinarian said we should put her on a medication called Proin (phenylpropanolamine), which would give more tone to the sphincter muscle that sits between the bladder and the vagina. But when we looked up phenylpropanolamine, we found that the drug, which we would have to give her for life, can have side effects ranging from mood disorders to difficulty breathing. That sounds awful. How should we proceed?
If we don’t see any abnormalities at all, we try medication. Note that despite phenylpropanolamine’s list of potential side effects (Proin is just one manufacturer of this drug), most dogs do not have a problem with it, even though they’re on it for life. The most typical reaction, if any, is a bit of hyperactivity — not surprising since the drug is somewhat similar to amphetamine. Phenylpropanolamine can also cause a mild increase in blood pressure. That’s not an issue for when a dog is young like yours, but can become one later in life if a dog develops heart or kidney disease.
How We Figure Out What’s Wrong: Diagnosing Incontinence
Fortunately, in most cases, we can narrow down urinary issues to incontinence pretty quickly, often with some good historical information.
As mentioned, dogs with incontinence characteristically leak urine without realizing it, especially when sleeping. When you bring your pup into your vet with urinary concerns, your vet will ask pointed questions about the nature of the urinary issues, when you’re seeing accidents happen, and how the behavior looks.
I also typically ask a lot of questions for young puppies about how potty training and crate training are going. Puppies have to drink and pee frequently when they’re active and sometimes new pet parents will confuse this behavior with incontinence when we really just need to work on our potty schedule and training.
We always typically rule out other common medical problems like urinary tract infections, by checking a urine sample first. In many cases, we’ll use an ultrasound to guide collection of a sterile urine sample. This also allows a look at the bladder to rule out bladder stones, polyps, and other bladder masses.
Some birth defects of the bladder can be identified with ultrasound, but not often with your regular vet. A specialist in ultrasound, like a veterinary radiologist, can sometimes diagnose ectopic ureters, a patent urachus, and other disorders of the upper urinary tract, as well as visualizing abnormalities in urine flow.
If an abnormality like an ectopic ureter is suspected, contrast study x-rays may be considered, where a special dye is used to highlight the urinary tract, allowing the abnormal path of one or both ureters to be seen.
The lower urinary tract (including the urethra and bladder) can also be directly visualized using an endoscope, which is kind of like a long tube with a camera on the end. Some general veterinary practices have scopes, but endoscopy is more commonly performed with an internal medicine specialist.
Lastly, advanced imaging like a CT scan or MRI may be considered. These methods allow for pictures of little tiny slices of the body to be taken, which makes it easier to highlight and identify the start and end of an anatomic abnormality.
While ultrasound and x-rays can typically be done with pets awake or lightly sedated, scoping and advanced imaging requires general anesthesia.