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