Urinary Incontinence in the Dog

If your housetrained dog starts having indoor accidents, it could have a medical condition that’s interfering with its normal elimination habits. With the help of your veterinarian a diagnosis may be determined. Promptly treating your dog will put an end to its discomfort - and your carpet-cleaning bills. And remember, reprimands are unfair and ineffective if your dog’s house soiling problem stems from a medical ailment.

Normally, a circular muscle (sphincter) at the end of the urethra (the urine conduit out of the body) restricts urine flow. As urine fills the bladder, nerves in the bladder wall send signals alerting the brain. The brain then sends a release command to the sphincter, and urine flows.

The most common form of urinary incontinence (loss of the voluntary control described above) is estrogen-responsive incontinence - a condition rarely affecting some spayed females. The common complaint regarding this form of incontinence is leaking of urine while your pet is resting or sleeping. Estrogen depletion, resulting from ovary removal during spaying, apparently causes weakness of the urinary sphincter.

Veterinarians treat this disorder with estrogen supplementation or phenylpropanolamine (PPA).

Phenylpropanolamine stimulates the secretion of norepinephrine, a hormonal substance that increases sphincter muscle tone. Side effects PPA are hyperexcitability. This medication must be administered 2-3 times daily.

Estrogen at low doses is safe and will replace the loss of the hormone due to being spayed. Concerns about adverse effects should be minimized. Side effects include bone marrow suppression (which we have never seen in our practice) and the possibility of causing a false heat if administering to high of a dose. This medication is dosed to effect. That means, it may be given once weekly up to 3-4 times per week, depending on your pets clinical response to this drug.

Another possible cause of incontinence is trauma to the brain or spinal cord. Depending on the degree of nerve damage, a dog with such a condition may dribble urine intermittently or constantly. Most dogs with neurologic incontinence also exhibit other nerve-related maladies, such as loss of coordination.

It’s important to quickly diagnose and treat any form of urinary incontinence. Chronic exposure to urine can cause secondary complications such as skin ulcers, especially in dogs that are immobilized.

Indoor accidents can occur when a dog has a medical condition that generates more than the usual amount of urine. Cushing’s disease, diabetes mellitus (sugar diabetes), bladder stones, liver disease, and chronic kidney failure are several examples. In Cushing’s disease, the adrenal glands produce excess cortisol, which blocks the action of antidiuretic hormone and thus stimulates the kidneys to increase urine output. In diabetes mellitus, the pancreas produces insufficient insulin, the hormone that transports glucose into cells. Glucose then builds up in the blood, and the kidneys excrete excess glucose in large volumes of urine. Dogs with chronic kidney failure also produce large amounts of urine because their kidneys can’t properly channel water back into the bloodstream.

Some dogs feel the urge to urinate frequently when they have urinary-tract infections. Irritation of the bladder wall due to infection can lead to reflexive bladder contractions . Bladder stones can also cause an irritation to the bladder causing an increased urge to urinate. Other bladder conditions causing the dysfunction are tumors and polyps of the bladder.

And sometimes drugs contribute to increased urine volume. For example, diuretic drugs used to treat heart disease stimulate the kidneys to excrete more urine.

In healthy dogs, the anal sphincter prevents release of feces until the rectum fills and stretches. When stretched, rectal muscles signal the dog to relax the sphincter and defecate. Damage to the brain, spinal cord, or spinal nerves can disrupt these signals, causing the dog to defecate involuntarily. However, the most common medical cause of fecal house soiling is diarrhea, often the result of inflammatory conditions of the colon.

To successfully treat medically related house soiling, you must address the instigating cause. Once diagnosed, many cases of illness- induced house soiling clear up with appropriate treatment. While dogs with incontinence due to neurological damage or chronic kidney failure may never regain total control, they often fare quite well if a committed caretaker helps them with their elimination duties and keeps them clean and dry.

Here are some clues your vet will use to identify medical causes of house soiling:

Age: In young dogs, veterinarians consider congenital disorders such as a misplaced ureter (the tube connecting the kidneys to the bladder). Diabetes mellitus is more common in middle-aged dogs. And elderly dogs may suffer from arthritis - which makes natural elimination postures painful - or from chronic kidney failure.

Gender: Female dogs are more prone than males to developing urinary-tract infections. And estrogen-responsive urinary incontinence occurs exclusively in spayed females.

Breed: Boston terriers, poodles, dachshunds, and German shepherds are among the breeds predisposed to Cushing’s disease. And long and low breeds such as dachshunds and basset hounds show higher incidences of intervertebral disk disease, which can result in spinal-nerve damage and subsequent incontinence.

Urination Frequency: Veterinarians often suspect Cushing’s disease, diabetes, or chronic kidney failure in dogs that drink and urinate excessively. But if your dog urinates frequently and strains in the process, it could have an infection, bladder stones, or a bladder tumor.