TL;DR: If your dog is straining but unable to urinate, they may have a life-threatening urethral obstruction requiring immediate emergency veterinary care to prevent kidney failure or bladder rupture.
What does it mean if my dog is straining but not urinating?
When a dog assumes the position to urinate frequently but produces little to no urine, it often indicates a urethral obstruction. This is a physical blockage—caused by stones, crystals, inflammation, or tumors—that prevents the bladder from emptying. It is a painful and distressing condition for your pet.
Is it a medical emergency if my dog cannot urinate?
- Seek emergency veterinary care immediately if your dog has not produced urine for several hours.
- Blocked urine causes toxins to build up in the bloodstream, leading to acute kidney failure.
- The condition can cause life-threatening electrolyte imbalances, heart failure, or a ruptured bladder.
How can a photo or video help the vet triage my dog?
- Capture a video to help the veterinarian distinguish between urinary straining (stranguria) and straining to defecate (tenesmus).
- Take photos of any small droplets of blood or sandy "grit" seen on the ground.
- Visual evidence provides the triage team with vital clues regarding the cause and severity of the blockage.
Clinical Context (Merck Veterinary Manual)
Urethral obstruction in dogs is an emergency requiring immediate treatment. Affected animals may exhibit frequent attempts to urinate, producing only a fine stream, a few drops, or nothing, and may cry out in pain. Complete obstruction leads to uremia within 36-48 hours, progressing to depression, anorexia, vomiting, diarrhea, dehydration, coma, and death within 48-72 hours. Physical examination reveals a distended, hard, and painful bladder if intact; rupture may provide temporary pain relief but leads to peritonitis, absorption of uremic toxins and potassium, depression, abdominal distention, cardiac arrhythmias, and death. Hyperkalemia and metabolic acidosis are life-threatening complications. Initial emergency care involves immediate relief of obstruction by catheterization and fluid therapy with normal saline.
Chapter: Urology, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 1527)