What are the most common causes of urinary tract obstruction in dogs and cats?

Common causes include urinary crystals or stones, urethral plugs, and urinary tract infections. Risk varies with age, sex, and diet — speak to your vet if you notice anything unusual.

My pet hasn't produced any urine but otherwise seems okay — is an emergency visit really necessary?

Complete absence of urine can quickly lead to dangerous electrolyte imbalances and kidney damage, even if the pet seems alert. Contact an emergency clinic as soon as possible so the vet can assess whether immediate intervention is needed.

What tests will the vet run to confirm a urinary tract obstruction?

Common diagnostics include a blood panel with electrolytes, urinalysis, X-rays, and an ultrasound to evaluate the bladder and urethra. The vet may also pass a urinary catheter or collect a urine sample by cystocentesis during the visit.

How can I reduce the risk of urinary tract obstruction in my pet?

Encourage regular water intake, offer wet food or a water fountain, maintain a healthy weight, and schedule routine urine checks. If crystals or stones have been found before, follow your vet's prescription diet recommendations closely.

How much do the tests and treatment for urinary tract obstruction usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Urinary Tract Obstruction in Dogs & Cats: Symptoms, Diagnosis & Care [2025]

A blocked urinary tract — from stones or a plug — is a life-threatening emergency; delayed treatment can be fatal.

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: ISFM, AVMA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate emergency care

•Continuous straining to urinate with little to no urine output
•Altered consciousness, including lethargy or stupor
•Abnormal gum color such as pale or purple

Schedule a clinic visit soon (within 24–72 hours)

•Frequent squatting attempts with very little or intermittent urine output
•Persistent licking of the urethral opening or signs of obvious discomfort
•Vomiting, noticeably reduced appetite, or decreased energy

01What signs indicate something is wrong?

Urinary tract obstruction can present with both systemic and urinary-specific signs; catching them early helps assess severity.

Lethargy or noticeably reduced activity level
Frequent attempts to urinate with little or no urine produced
Repeated vomiting or significant loss of appetite
Frequent licking at the urethral opening or obvious discomfort when urinating
Abnormal heart rate or signs of dehydration (reduced skin elasticity)
Abnormal urine colour, cloudiness, or blood in the urine — seek veterinary attention promptly

Seek emergency care immediately if you notice the following symptoms:

⚠️ Straining hard to urinate but producing no urine at all
⚠️ Altered consciousness, extreme drowsiness, or severe weakness
⚠️ Abnormal gum or lip colour (pale, white, or bluish-purple)

02How to assess the situation at home — what to observe and when to go to the emergency clinic

Tracking these details at home before your visit helps the vet quickly understand your pet's condition and how it has changed.

Note changes in alertness and activity (when did they start, are they getting worse?)
Record the number of vomiting episodes, the appearance, and the timing
Measure and log daily water intake (using a measuring cup gives the most accurate results)
Track urination frequency and estimate output volume each time (noting any complete absence of urine)
Film your pet attempting or completing urination — the footage helps your vet significantly
Weigh your pet over a short period and record any changes; consult your vet early if there is a drop

03How will the vet diagnose this? Common tests and procedures

The vet will use imaging and laboratory tests to confirm obstruction and identify any secondary electrolyte or kidney complications.

Physical examination

abdominal and bladder palpation to check for distension or pain

Blood panel

kidney function markers and electrolytes (especially potassium)

Urinalysis and bacterial culture to evaluate infection or crystal type

Abdominal ultrasound to assess the bladder and urethra

X-rays to detect bladder stones or structural abnormalities of the urinary system

CT scan for more detailed imaging when required

Urinary catheterisation or cystocentesis may be performed to relieve pressure and collect a urine sample

Visiting a hospital with imaging capability and urinary-procedure expertise is recommended

04Treatment and aftercare: medications, dietary changes, and home management

After emergency stabilisation, ongoing management involves medication, dietary adjustments, and regular monitoring — with close attention to the risk of recurrence and complications.

Acute management typically involves urinary catheterisation or bladder decompression to restore urine flow
Antibiotics may be prescribed if a concurrent infection is detected
A prescription diet may be recommended to reduce crystal and stone formation
After discharge, monitor daily water intake and urination frequency closely
Follow up with your vet as scheduled for blood, urine, and imaging rechecks
Home care includes restricting activity and watching for any return of symptoms
If symptoms recur or worsen, return to your vet immediately or refer to a specialist hospital

05What to prepare before the vet visit — information that helps the vet pinpoint the cause quickly

Record a short video of your pet attempting or completing urination to show the vet

Note urine colour, presence of blood, or any unusual odour and describe it to the vet

Log daily water intake and urination frequency with timestamps

Document when symptoms began and how they have progressed (e.g. when did things get worse?)

Bring a list of any current medications or supplements your pet is taking

Bring any previous test results or imaging (X-rays, ultrasound reports)

Use a secure carrier and call ahead to arrange a scheduled or emergency appointment

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Related Symptoms (You May Also Be Looking For)

Bradycardia

Abnormally slow heart rate

Fluid deficit

Blood in urine

Low body temperature

Decreased activity

Changed mental state