Pet Care

Medical Causes of House Soiling in Dogs

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House soiling, or inappropriate urination or defecation, is a common problem in dogs. While in many cases house soiling is due to a behavioral problem, sometimes medical issues are to blame. It may be difficult or even impossible for a pet parent to distinguish between behaviorally caused house soiling and medically caused house soiling. For this reason, the first step in solving a house-soiling problem is to take your dog to a veterinarian for a thorough check-up and urinalysis.

Bacterial Bladder Infection

Bacterial cystitis (a bladder infection) or bladder stones can cause increased frequency of urination, straining during urination and, sometimes, bloody urine. Diagnosis of a bacterial infection is done by urinalysis, culture and sensitivity. Radiographs or ultrasound may be used to find bladder stones.

Urinary Incontinence

Animals with urinary incontinence tend to dribble urine. This can occur when a dog is awake or while she’s sleeping. Urinary incontinence is common in dogs, particularly in spayed females. Studies have reported that the incidence of urinary incontinence in dogs following ovariohysterectomy (spay surgery) ranges from 13% to 20%.

A number of physical problems can cause urinary incontinence:

  • Decreased sphincter control, which is most commonly seen in older spayed females
  • Anatomical abnormalities, such as ectopic ureters, urethral sphincter incompetence, patent urachus, idiopathic detrusor instability, ureterovaginal fistula, pelvic bladder, vaginal stricture/vaginal urine pooling and ureterocele
  • Urge incontinence or paradoxical incontinence
  • Damage to a dog’s nerves or spinal cord that innervate the bladder (trauma, neoplasia)

Diagnosis of urinary incontinence may include a urinalysis and contrast studies. Anatomic abnormalities may be identified by radiographs or abdominal ultrasound. CT scans or cystoscopic exams may be used in some cases.

Increased Urine Production

Polyuria, or increased urine production, has many causes and is common in dogs. Dogs with polyuria produce large volumes of urine without straining. Other signs of this problem may include increased water intake, decreased appetite and weight loss.

Causes of polyuria include kidney (renal) disease, chronic renal failure, pyelonephritis, primary renal glycosuria (Fanconi's Syndrome), pyometra, liver disease and polycythemia. Endocrine diseases, such as diabetes mellitus, diabetes insipidus, hyperadrenocorticism (Cushing’s disease), hypoadrenocorticism (Addison’s disease) and hyperthyroidism, can all cause polyuria. Hypercalcemia and hypokalemia can also cause increased urination. Certain medications, such as exogenous steroids, diuretics, anti-convulsants, potassium bromide and vitamin D, can cause polyuria. A rare cause of increased urine production is primary polydipsia, also known as psychogenic polydipsia. Dogs with this problem drink excessive amounts of water without an underlying cause. If your dog has been diagnosed with primary polydipsia, please see our article, Compulsive Behavior in Dogs, for more information.

Diagnosis may include a urinalysis (urine specific gravity and glucose), chemistry panel and other blood tests, contrast radiography and vaginal exam. Depending on the results, more diagnostics, such as a modified water deprivation test, may be needed.

Inappropriate Defecation

Inappropriate defecation is much less common in dogs than inappropriate urination. Possible medical causes include inflammatory bowel disease (IBD), anal sac problems and food sensitivities. Older dogs may defecate indoors due to locomotion issues (a dog may be unable to stand due to arthritis, for example) or dementia (cognitive dysfunction syndrome). Diagnosis may require fecal exams, biopsies and dietary changes.