Urination problems involve either storing urine or passing it. Urinary incontinence means a dog can't control urination. It may leak urine all the time or only sometimes. Wet fur and skin irritation around the genital area are common with incontinence (inability to control urination).
Problems With Urine Storage in Dogs
Some dogs have difficulty holding their urine. This is called a urine storage problem, and it can cause the dog to leak urine. Causes include weak muscles in the bladder or urethra, birth defects, injury, or bladder overfilling. "Urge incontinence" is a strong need to urinate resulting in leakage, and it is often caused by bladder irritation. Low levels of sex hormones in neutered dogs, especially females, can also cause incontinence. Problems with the urethral sphincter (the muscles that control the release of urine from the urethra, the tube that carries urine from the bladder out of the body) are another cause.
Birth defects, such as an ectopic ureter (see Congenital and Inherited Disorders of the Urinary System in Dogs), often cause signs of incontinence in young dogs. A partially blocked urethra can also lead to overflow leakage.
Problems With Urine Elimination in Dogs
Dogs that can't "go" are said to have urine elimination problems, and they can't empty their bladder well. Causes include urinary stones (see Urinary Stones in Dogs), growths, scar tissue, nerve disorders, and weak bladder muscles. Dogs with elimination problems often strain, urinate slowly, and pass only small amounts of urine. Over time, the bladder might overfill and leak.
Neurological Problems Affecting Urination in Dogs
Nervous system problems can affect your dog's urination (see The Nervous System of Dogs). Damage to the lower spine, pelvic nerves, or bladder muscle control can cause a large bladder that empties easily when pressed. Damage to the upper spine or brain can cause a large bladder that doesn't empty easily. Poor muscle coordination can also interrupt normal urine flow. Some dogs with neurological diseases leak urine because the bladder overfills.
Diagnosis and Treatment of Urination Problems in Dogs
Diagnosis of your dog's urination problem starts with a veterinarian taking a medical history and conducting a physical exam. The vet may watch your dog urinate. Additional tests might include ultrasound, x-rays, a visual exam of the urinary tract with an instrument called a cystoscope, or neurological testing.
Treatment depends on the cause of the problem. Hormones can help some dogs with hormone-related incontinence. Other drugs can help the urethra to tighten, calm an overactive bladder, improve bladder contraction, or improve muscle coordination. A completely blocked urethra blockage is an emergency and might require insertion of a catheter (a tube to help drain urine from the body) or surgery (see Urinary Emergencies in Dogs).
If a dog's bladder has been stretched for too long, repeated catheter use might be needed for several days to keep the bladder empty until bladder muscle can contract normally again. Dogs with permanent nerve-related loss of bladder tone might need lifelong help emptying its bladder. Owners might need training in how to use a catheter or manually express (squeeze) the bladder.
For More Information
Also see professional content regarding urination (micturition) problems in dogs.
