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Dog Not Peeing After TPLO Surgery: Causes & Care

Dog Not Peeing After TPLO Surgery: Causes & Care

TPLO

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Owners

Learn why your dog may not pee after TPLO surgery and how to manage this common post-op issue safely and effectively.

By 

Sustainable Vet Group

Updated on

August 13, 2026

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This article is for informational purposes only and is not a substitute for professional veterinary advice. Every case is unique, so always consult your veterinarian for guidance specific to your pet.

This content is intended for veterinary professionals for educational purposes. It does not replace clinical judgment or tailored advice. Always rely on your training, expertise, and the specific context of your patients.

Dog Not Peeing After TPLO Surgery: Causes & Care

It is common to notice changes in a dog's urination pattern in the first 24 to 48 hours after TPLO surgery.

Most of these changes are temporary and related to the effects of anesthesia, pain medications, and reduced mobility.

However, not urinating at all for more than 12 to 24 hours is a clinical concern that requires prompt veterinary contact.

 

Quick answer: Reduced urination in the first 12 to 24 hours after TPLO is usually caused by anesthesia effects, opioid medications, pain, or stress. Contact your vet immediately if your dog has not urinated within 12 hours post-surgery, or if you observe straining, vocalization, or abdominal distension.

 

Key takeaways

  • Reduced urination in the first 12 to 24 hours is normal: anesthesia suppresses bladder awareness and opioids reduce the sensation of fullness
  • Contact your vet if no urination occurs within 12 hours post-surgery: this is the critical threshold, per published veterinary guidance do not wait
  • Straining, vocalizing, or abdominal swelling requires same-day veterinary evaluation: these signs suggest urinary retention requiring catheterization
  • Opioid pain medications are the most common pharmacological cause: they reduce bladder filling sensation and sphincter tone in some dogs
  • Surgical catheterization during the procedure may temporarily affect urination for 12 to 24 hours after catheter removal
  • Increased water intake without urination is particularly concerning: it suggests the dog is producing urine but cannot eliminate it a potential retention emergency

Why dogs may not urinate normally after TPLO

Anesthesia effects

General anesthesia suppresses the entire nervous system, including the neural pathways that signal bladder fullness and initiate voiding.

As anesthetic agents clear over the first 12 to 24 hours, normal bladder signaling gradually returns.

Most dogs produce less urine during anesthesia because of reduced blood pressure and fluid redistribution.

When fluid therapy resumes and hydration normalizes after surgery, urine production increases but the dog must also have recovered enough neurological function to void normally.

Opioid pain medications

Opioid analgesics (hydromorphone, morphine, buprenorphine) prescribed after TPLO affect urination in two main ways.

They reduce the perception of bladder fullness, so the dog does not signal readiness to urinate as promptly as usual.

In some dogs they also increase urethral sphincter tone, making voiding more difficult.

JustAnswer veterinary consultation confirms: opioids can cause urinary retention by relaxing or altering bladder muscles, making it hard for the dog to pee.

This effect is temporary and typically resolves as opioid dosing decreases over the first 48 to 72 hours.

Pain and reluctance to posture

Urination requires the dog to posture squatting or lifting a leg both of which require hindlimb use and core stability that are painful in the first days after TPLO.

A dog that finds posturing too painful may suppress the urge to urinate or produce only small amounts.

Providing a non-slip surface, a low slung outdoor space (not steps or slopes), and supporting the dog with a belly sling during outdoor trips reduces posturing pain and encourages normal urination.

Surgical catheterization

A urinary catheter is often placed during TPLO surgery to drain the bladder, keep the surgical field dry, and prevent accidents during the procedure.

After catheter removal, some dogs take 12 to 24 hours to resume normal voiding patterns as the urethra recovers from catheter placement and the bladder regains normal tone.

Stress and unfamiliar environment

Dogs in pain, in an unfamiliar post-surgical environment, and wearing an E-collar may suppress urination due to stress.

Stress-related urinary suppression is temporary and usually resolves as the dog settles into the home recovery environment.

Normal urination expectations after TPLO

Most dogs urinate at least once within 6 to 12 hours of returning home from surgery. By 24 hours, most dogs have urinated multiple times.

The SustainableVet.org dog-not-peeing guide confirms: if your dog does not pee within 24 hours post-surgery, contact your veterinarian immediately to rule out complications.

The published veterinary guidance for emergency contact is: no urination within 12 hours post-surgery contact your vet.

Signs that require immediate veterinary contact

Contact your veterinarian same-day or go to an emergency clinic if you observe:

No urination at all for 12 or more hours after surgery: this is the key threshold do not wait to see if it resolves

Straining or crying during urination attempts: the dog is trying to urinate but cannot produce a stream classic urinary retention sign

Abdominal distension: the belly feels full or tense; this suggests a distended bladder (urinary retention emergency)

Drinking water but producing no urine: urine is being produced but cannot be eliminated urgent

Vomiting or lethargy alongside no urination: systemic signs accompanying urinary retention indicate a more serious emergency

Urinary retention: what happens and how it is treated

Urinary retention means the bladder cannot empty. The bladder fills progressively and becomes painful, distended, and eventually at risk of rupture if unrelieved. Prolonged retention also causes back-pressure on the kidneys.

Treatment depends on the cause:

  • Catheterization: gentle placement of a urinary catheter to drain the bladder provides immediate relief and allows the bladder to recover normal tone
  • Pain management adjustment: if opioid-induced retention is suspected, the analgesic protocol may be modified
  • Bethanechol: a parasympathomimetic drug that stimulates bladder contraction; sometimes used in dogs with neurogenic urinary retention
  • Urinalysis and culture: if infection is suspected alongside retention

Home care to encourage urination

  • Scheduled outdoor trips every 2 to 4 hours for the first 24 to 48 hours
  • Non-slip surface outdoors pain and weakness increase slipping risk
  • Gentle belly-sling support to reduce posturing pain (fold a large towel under the belly and lift slightly)
  • Quiet, calm outdoor environment stressed dogs suppress urination
  • Adequate pain control contact your vet if your dog is vocalizing or reluctant to move; these are signs pain medication is insufficient
  • Monitor and record each urination: time, approximate volume, any straining or discomfort

For the related incontinence guide (opposite problem), see dog incontinence after TPLO surgery: causes and care. For the post-surgical pain guide, see dog whining after TPLO surgery: causes and care.

For the full recovery guide, see what to expect after TPLO surgery in dogs. For the monitoring guide during early recovery, see post-operative care mistakes increasing TPLO infection risk.

Frequently asked questions

How long after TPLO surgery should my dog urinate?

Most dogs urinate within 6 to 12 hours of returning home from surgery. Contact your veterinarian if no urination has occurred within 12 hours.

Do not wait for the 24-hour mark if the dog is straining, vocalizing, or appears uncomfortable.

My dog is drinking water but not peeing at all. Is this an emergency?

Yes. A dog that is drinking and producing urine but cannot eliminate it (retention) needs same-day veterinary evaluation. A distended bladder is painful and can rupture.

Do not manage this at home contact your vet immediately.

Can opioid pain medications cause urinary retention?

Yes. Opioids are a recognized cause of urinary retention in both humans and dogs.

If your dog was urinating normally before surgery and stops after receiving opioid medications, this is likely a contributing factor.

Contact your vet the analgesic protocol may be modified without eliminating pain management.

What does a catheter placement during surgery do to urination afterward?

Urinary catheters are placed during TPLO to drain the bladder and keep the surgical field dry.

After catheter removal, some dogs take 12 to 24 hours to resume normal voiding as the urethra recovers.

This is expected and not a cause for alarm, as long as the dog urinates within the normal timeframe.

Is it safe to give my dog extra water if they're not peeing?

Normal hydration is essential and should be maintained. Do not restrict water.

However, if the dog is drinking normally and still not producing urine, this increases the urgency of veterinary contact rather than reducing it.

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