Urethral sphincter mechanism incompetence in dogs

Updated 2026-09-30 · 1 sources

Based on: PDSA

Book a vet visit

Book a vet appointment if you think your dog has this – a vet needs to confirm it and plan the treatment. It is when the urethra, the tube that carries urine out of the body, becomes weak and leaky.

What to do now

What you can do now

  1. Contact your vet about your dog's signs
  2. Note when it started, how often it happens and what else you see
  3. Take a photo or short video to show the vet
  4. Keep fresh water available
  5. Let your dog rest somewhere calm

Don't

  • Do not give any human medicine
  • Do not wait if it gets worse

What it is

Urethral sphincter mechanism incompetence is when the urethra becomes weak and leaky.[1] It is a common cause of urinary incontinence in dogs.[1]

Signs

  • Urine dribbling, especially when lying down or sleeping
  • Urine staining around the vulva or penis
  • Urine infections
  • Peeing normally the rest of the time

How a vet finds out

  • Physical examination
  • Urine tests
  • Blood tests

How vets treat it

  • Medication to tighten the urethra
  • Medication may come as a liquid or tablet
  • Medication given daily for the rest of the dog's life
  • Rest

What the experts say

“Overview. Does your dog leak urine? Especially when they are lying down? They could be suffering from USMI - a common cause of urinary incontinence in dogs. USMI is when the urethra (the tube that carries urine out of the body) becomes weak, and leaky.”

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

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Common questions

What signs can urethral sphincter mechanism incompetence cause?

Signs can include urine dribbling, especially when lying down or sleeping, urine staining around the vulva or penis, urine infections, and peeing normally the rest of the time.[1]

How will a vet find out if my dog has it?

A vet may use a full examination, urine tests and possibly blood tests, while ruling out other possible causes of incontinence.[1]

How may a vet treat it?

Treatment is often medication to tighten the urethra, given as a liquid or tablet daily for the rest of the dog's life.[1]

Sources

  1. PDSA

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

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