A small red or purple lump at the tip of a young male dog's penis, often with licking or a few drops of blood, is the classic picture of urethral prolapse. It is not considered life-threatening, but it does not go away on its own, it is usually treated with surgery, and it can come back.
Watch: urethral prolapse repair in a bulldog
This 65-second clip from the Graham DVM channel shows a bulldog with a clinically significant urethral prolapse and the repair, which trims and tacks the redundant urethral tissue.
What is urethral prolapse?
The urethra is the tube that carries urine from the bladder out of the body. In urethral prolapse, the inner lining of the very end of the urethra pushes out through the opening at the tip of the penis, so it becomes visible. It is seen almost only in male dogs.
The prolapsed tissue usually looks like a pea-sized, doughnut-shaped mass, red to purple in color. The exposed lining inflames easily and may bleed.
Which dogs get it?
Most affected dogs are young, intact (not neutered) males: one specialist reported a mean age of about 18 months, and a 2025 series of 20 dogs had a median age of 10 months.
English bulldogs are by far the most affected breed. A 2014 study of 48 dogs found English bulldogs had about 367 times the odds of urethral prolapse compared with all breeds combined. Other brachycephalic (flat-faced) breeds such as Boston terriers and pugs are also over-represented, making up 75-80% of cases in two recent series. Yorkshire terriers have been reported too.
What causes it?
Nobody knows for certain. The main hypotheses are:
- Raised pressure inside the abdomen from labored breathing in brachycephalic obstructive airway syndrome (BOAS), coughing, or straining to urinate or defecate.
- Sexual excitement. The prolapse has been observed to be more severe in sexually active males.
- Urinary tract problems such as bladder infection, cystitis (bladder inflammation) or stones, which is why vets often check the urine and bladder.
- Abnormal development of the urethra itself, suspected in bulldogs and similar breeds.
Signs to watch for
- A small red or purple lump at the tip of the penis (you may only see it when the penis is out of the prepuce, the sheath)
- Licking of the penis or prepuce
- Blood in the urine, or blood dripping from the prepuce or penis
- Straining to urinate
In the 2025 series, half the dogs had bleeding from the penis and 30% had blood in the urine. Some dogs show no obvious signs at all.
How vets diagnose it
The vet usually diagnoses it on physical exam by moving the prepuce back and seeing the prolapsed tissue. Because the cause matters for treatment, they may also recommend a urinalysis and urine culture to look for infection, and X-rays or ultrasound to check for stones. In English bulldogs, which are prone to urate and cystine stones that may not show on X-rays, ultrasound is generally preferred. Cytology or a biopsy helps if the mass could be a tumor.
Treatment options
Your veterinarian chooses the approach based on how large and damaged the tissue is, whether it bothers the dog, and any underlying cause.
- Manual reduction. Under general anesthesia, the vet pushes the tissue back in and places a temporary stitch at the urethral opening. This can work for a small prolapse, but recurrence is common.
- Surgery. The two standard procedures are resection and anastomosis (removing the prolapsed tissue and reattaching the healthy urethral lining) and urethropexy (stitching the urethra in place so it stays put). Some surgeons combine them. Surgery is strongly recommended when there is heavy bleeding, discomfort, badly damaged tissue, or a prolapse that came back after manual reduction.
- Monitoring. The prolapse will not resolve without treatment, but one specialist described an untreated bulldog with no signs whose prolapse stayed unchanged for four years. A small prolapse causing no bleeding or discomfort is sometimes watched instead. That is your vet's call, not a reason to wait and see on your own.
Your vet will give aftercare instructions, which often include a cone to stop licking and keeping the dog calm; some bleeding after surgery is common.
Does castration help?
Castration (neutering) is often recommended alongside treatment to prevent recurrence, but the evidence is mixed. The 2014 study found castration status did not seem to affect prolapse development or outcome, and a 2026 series of 21 dogs found it did not change the risk of complications. A 2024 study of 46 dogs went the other way: dogs neutered before diagnosis may be more likely to have a recurrence. If your vet recommends it, it is fair to ask what they expect it to achieve for your dog.
Will it come back?
Recurrence is the most common complication after treatment, and how often it happens depends heavily on the study and the technique:
Study | Dogs | Recurrence |
|---|---|---|
Carr et al., 2014 (2 referral centers, 1995-2010; mostly resection and anastomosis) | 48 | 57% of dogs with long-term follow-up |
Healy et al., 2024 (10 referral hospitals in the UK, Ireland and Italy) | 79 | 26.6% overall: urethropexy 38.6%, resection and anastomosis 11.1%, combined 12.5% |
Grewal et al., 2024 (3 hospitals) | 46 | Resection and anastomosis 48%, urethropexy 33%, combined 8% |
Mas et al., 2025 (1 hospital in Montréal; urethropexy) | 20 | 10% |
So reported recurrence runs from about 1 in 10 dogs to more than half. The studies even disagree on which technique recurs least, and all four are retrospective with different patients and follow-up, so the numbers are not directly comparable.
Some dogs need more than one surgery. In the 2026 series, 6 of the 8 dogs whose prolapse recurred had revision surgery, and one eventually needed part of the penis removed.
The overall outlook is still good. Specialist guidance for owners describes the prognosis with surgery as excellent.
When to see your vet
Book a visit if you see any red or purple lump at the tip of your dog's penis, or blood from the prepuce or in the urine. Don't try to push the tissue back yourself; manual reduction is done by the vet under general anesthesia. Mention any noisy breathing, coughing or straining too, since those may be part of the cause.
For more surgery footage, see our vaginal prolapse surgery video (a different condition, in female dogs) and the perineal hernia surgery video.
Sources
- Veterinary Surgery: Carr JG, Tobias KM, Smith L, Urethral prolapse in dogs: a retrospective study, 2014
- Journal of Small Animal Practice: Healy D et al., 2024, multicenter study of urethral prolapse surgery in 79 dogs
- Journal of the American Animal Hospital Association: Grewal MK et al., 2024, urethral prolapse treatment outcomes in 46 dogs
- New Zealand Veterinary Journal: Mas P et al., 2025, urethropexy outcomes in 20 dogs
- Canadian Veterinary Journal: Lu HY et al., 2026, urethral prolapse outcomes in 21 dogs
- dvm360: How would you manage a prolapsed urethra in an English Bulldog? (Carl A. Osborne, DVM, PhD, DACVIM)
- Dallas Veterinary Surgical Center: Urethral Prolapse
- Veterinary Specialty Center Sarasota: Urethral Prolapse in Dogs, client handout by Cathy E. Langston, DVM, DACVIM
- YouTube, Graham DVM: Urethral prolapse and repair in a Bulldog
This article is for general information and is not a substitute for advice from your veterinarian.
