[From Tufts September 2012 Issue]
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?
Wesley Gilbert
Mankato, Minnesota
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.
Once infection is ruled out, an abdominal ultrasound of the entire urinary tract will help determine whether the dog has an ectopic ureter. The two ureters are long, narrow tubes that take urine from the kidneys to the bladder. If one or both ureters empty below the bladder, in the urethra or, in severe cases, the vagina, it’s ectopic (meaning in the wrong location) and requires a fix.
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.
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.
Best of luck solving your dog’s problem. Let us know how it turns out.
