SYMPTOM
Urinary incontinence
Owners may observe urinary incontinence in their pet, which can present in various ways depending on the underlying cause.
Neurological
Conditions affecting the nerves that control bladder storage and emptying can lead to involuntary urine loss. This may involve spinal cord changes, nerve compression, or disruption of the signals between the brain, spinal cord, and bladder wall.
Hormonal
Changes in hormone levels, particularly oestrogen in spayed female dogs, can affect the tone of the urethral sphincter—the muscle that keeps urine contained. When sphincter tone declines, urine may leak during rest or mild exertion.
Structural
Anatomical variations or changes in the bladder, urethra, or surrounding tissues can alter how urine is stored and released. This may involve congenital differences, scarring from previous inflammation or surgery, or positional shifts within the pelvis.
Inflammatory or infectious
Irritation or infection of the bladder lining can increase urgency and reduce the threshold for voiding, sometimes resulting in small-volume leaks. Inflammation may also affect the coordination between bladder contraction and sphincter relaxation.
Age-related
Older animals may experience gradual weakening of pelvic musculature, changes in bladder wall compliance, or cognitive shifts that alter awareness of bladder fullness. These patterns can overlap with other age-associated changes in mobility and general health.
Behavioural or environmental
In some cases, apparent incontinence may reflect difficulty accessing usual toileting areas, reluctance to adopt normal postures due to discomfort elsewhere, or learned patterns related to past experiences. Distinguishing involuntary leakage from voluntary but poorly timed urination can matter.
Why timing matters
Early observation
When incontinence first appears, the pattern of leakage can offer clues about the underlying mechanism. Small volumes during rest or sleep may point towards reduced sphincter tone, whilst larger volumes or leakage during activity may suggest bladder over-distension or incomplete emptying. The presence or absence of awareness—whether the animal seems surprised by the leakage—can also be informative.
Later presentation
If incontinence continues or worsens over weeks to months, it may indicate progression of an underlying process, inadequate compensation by surrounding structures, or the emergence of secondary changes such as skin irritation or behavioural adjustments. Persistent leakage can also make it harder to distinguish the primary pattern from adaptive changes in drinking, posture, or toileting behaviour.
Some forms of incontinence remain stable for extended periods, particularly when tied to stable hormonal or structural factors. Others may fluctuate with activity level, weight, hydration, or concurrent illness. Individual variation in pelvic anatomy, muscle tone, and compensatory capacity means that two animals with similar underlying patterns can follow quite different trajectories over time.
Conditions commonly associated
Degenerative Myelopathy
Advanced disease affects the nerves controlling bladder function, leading to loss of control.
Urinary Tract Infection in Dogs
Urinary tract infections can cause inflammation and irritation of the bladder lining, which may reduce the bladder's ability to hold urine normally and lead to leakage, particularly when the infection affects the sphincter tone or triggers urgency that the animal cannot control.
Feline Idiopathic Cystitis
Feline idiopathic cystitis involves inflammation of the bladder wall that can disrupt normal bladder function and sensation, sometimes resulting in involuntary urine leakage alongside other urinary signs such as frequency or straining.
Prostate Disease
Prostate disease in male dogs can cause the gland to enlarge or become infected, placing pressure on the urethra or affecting the sphincter mechanism that controls urine release, which may result in dribbling or leakage.
Transitional Cell Carcinoma
Transitional cell carcinoma tends to develop in the region where the bladder meets the urethra, and tumour growth in this area can interfere with the normal closure of the urinary sphincter or alter bladder wall compliance, leading to involuntary urine loss.
Degenerative Myelopathy in Dogs
Degenerative myelopathy involves progressive loss of nerve function in the spinal cord, and when the affected segments include those controlling bladder sphincter tone, incontinence can develop as the signals governing voluntary urine retention are weakened or lost.
When to explore further
If leakage occurs frequently enough to affect the animal's comfort, create hygiene challenges, or require significant changes to household routines.
If incontinence appears alongside other changes such as increased thirst, altered appetite, shifts in gait or posture, or difficulty rising or settling.
If the volume, frequency, or timing of leakage changes noticeably over days to weeks, or if the animal begins to show awareness or distress around the leakage.
If there is visible blood in the urine, straining to urinate, or signs of discomfort when attempting to void.
If the incontinence emerges following recent surgery, injury, or a period of illness, or if it coincides with the introduction of new medications or dietary changes.
Urinary incontinence gains meaning in the context of the animal's age, reproductive history, body condition, and any other observations over the same timeframe. Keeping a loose record of when leakage occurs, the volumes involved, and any accompanying behaviours can help clarify the pattern. This picture, alongside the animal's broader history and physical findings, shapes the conversation about what might be contributing and what options may be worth exploring.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS