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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.

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.