Diagnosing and treating urinary incontinence

Some dog owners fear that urinary incontinence is a natural result of aging and delay taking their dog to the veterinarian. While many dogs do develop age-related problems, there are many other causes to consider too. Urinary incontinence is easily treated, and the medications are not expensive, so the sooner you get your dog to the veterinarian, the better.

Causes of incontinence in dogs

Before you jump to conclusions, first make sure that the dog is indeed suffering from incontinence. A dog who is frightened or feels threatened may urinate. This is called submissive urination and it mainly affects young dogs. It is normally something they outgrow. A male dog that is not neutered will mark his territory, or a dog may simply need more housetraining.

Sometimes age does play a part in an older dog who may be suffering from canine cognitive dysfunction and simply forgets his housetraining. If all of these causes are ruled out, your dog will likely be diagnosed with urinary incontinence.

The first thing your veterinarian will do is perform a urinalysis and urine culture. The urinalysis finds certain cell types and biochemical elements in the dog’s urine while the culture grows the bacteria in the urine for identification purposes and to test different antibiotics to see which one would be most effective in fighting that particular strain.

Most incontinence is caused by:

  • A urinary tract infection (usually a bladder infection)
  • A weak bladder sphincter (common in aging female dogs)
  • Excessive water consumption
  • Spinal cord disease

Bladder infection

A bladder infection is a common cause of urinary incontinence in young adult female dogs and is generally diagnosed with a urine culture, although signs of the infection will usually show up in the urinalysis. In this case, the urine culture will confirm the diagnosis, identify the infecting bacteria and list the antibiotics that will be most effective in clearing the infection.

There are usually several choices of antibiotics and your veterinarian will choose the one most suited to your dog. The dog takes one to three weeks of medication, after which you should have a second culture done to ensure that the infection is truly cleared up.

Incontinence caused by a bladder infection will sometimes show an improvement only a few days after treatment begins, but it is important to finish the entire regimen to avoid a recurrence.

Weak bladder sphincter

Several factors, such as aging, obesity, and reduced sensitivity of the neurologic receptors in the sphincter, can contribute to this condition. It’s a common problem in older female dogs, with one in five dogs affected. This is also sometimes call spay incontinence and is believed to be caused by low estrogen levels. Once other conditions have been ruled out, the weak sphincter may be treated symptomatically using one of several medications.

  • Estrogens. Estrogens play a role in the maintenance of neuroreceptors in the bladder sphincter. Without estrogens, a common problem in spayed females, the receptors ignore the message to store the urine and it leaks out, often while sleeping. The estrogen DES (diethylstilbestrol), is the most common estrogen for dogs. Although DES is no longer considered safe for humans, the low dosage required for dogs is considered safe. The medication has to be ordered through a compounding pharmacy. The normal dose is 1mg once a day for five days and then once every four to seven days thereafter. A male dog seems to respond better to testosterones, but the dog must be watched for aggression issues, which are sometimes a side effect of the therapy.
  • Alpha-Adrenergic Agonists. These medications act by increasing the pressure of the bladder neck and helping to hold urine in the bladder. The most common medication for canine use is phenylpropanolamine, taken orally in pill form or as a liquid. Side effects of the medication can, but does not always, include irritability, loss of appetite, anxiety, and blood pressure changes. Most dogs, both male and female, have few problems with the side effects of phenylpropanolamine.

Your veterinarian may prescribe a combination of estrogens and alpha-adrenergic agonists to be used in particularly resistant cases.

  • Anticholinergics. Anticholinergic drugs work to relax the muscles of the bladder where the urine is stored, thus facilitating storage. A human anti-anxiety drug, Imipramine, has anticholinergic properties and can be used in combination with phenylpropanolamine to treat canine incontinence, but is used only in cases that do not respond to traditional therapies.

Excessive water consumption

Some dogs consume such large quantities of water that their bladders simply cannot hold it all. Some owners are aware that their dogs are drinking a lot of water, but most are surprised when the urinalysis shows that the dog has dilute urine.

That probem is easily detected through a measurement called “specific gravity” which compares the amount of dissolved biochemicals in the dog’s urine to pure water, which contains none. A urine specific gravity approximately equal to the water confirms excessive water consumption. Your veterinarian will probably order blood tests to determine if your dog has an underlying disease that would cause him to drink excessively.

Some causes of excessive water consumption include:

There are other, less common causes, but a blood panel and urine culture will disclose the presence or prove the absence of 90 percent of them.

Surgical intervention

When none of the traditional medicines work for urinary incontinence, there are surgical options available: colposuspension and cystourethropexy.

Colposuspension is a surgical procedure that repositions the bladder neck of female dogs in the intraabdominal cavity so that pressure from the wall muscles act simultaneously on both the bladder and the urethra. Thus, increased pressure on the bladder is met with increasing resistance from the urethra, enabling the dog to control herself.

There have been various studies of this surgery done over the years and most have shown a cure rate of approximately 45 to 50 percent and a marked improvement in roughly 75 percent of the remaining dogs. This surgery is not a cure-all and many dogs will still need to take some form of medication for the rest of their lives.

Cystourethropexy is the equivalent of the female surgery colposuspension, but it is for male dogs. In this surgery, the ductus deferens are tacked down to compress the urethra, helping to hold in the urine. The surgeon may also tack down fibers from the urethral muscles in either male or female patients.

These two surgeries improve the conditions of approximately 50 percent of patients, but there is a high incidence of relapse with the passing of time, and medications are also needed. Doctors have recently been exploring the use of laparoscopic surgery, but to date no studies have been carried out.

Unusual causes of incontinence

The list of causes and treatments above has just scratched the surface of incontinence. Some of the less common causes include:

  • Spinal damage, usually in the lower lumbar region
  • An infection located high in the urinary tract, usually of the kidneys or ureter
  • An ectopic ureter is an abnormally placed ending of the ureter. Instead of ending in the bladder, it drains into the urethra, the vagina or the uterus and the dog is constantly dribbling urine. It can be easily corrected with surgery.

Your veterinarian can answer any questions you may have about the best treatment for your dog. Do not try to medicate the dog with consulting your veterinarian.

Source: Adapted from the Veterinary Information Network, Inc.