Persistent Erection (Priapism and Paraphimosis) in Dogs

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Last updated on
2 min read

Key takeaways

Persistent erection can present as priapism, where the penis is persistently erected without sexual stimulation, or as paraphimosis, where the penis is extended but not erected.

  • Persistent extension and swelling of the penis is a medical emergency as this symptom has the potential to prevent passage of urine, which is life-threatening
  • Possible causes for persistent erection in dogs include injury during matin or manual semen collection, penile masses, vascular abnormalities, drugs, myelopathy, infection; a genetic predisposition is suspected
  • Diagnostics may include physical examination, medical history, diagnostic imaging, urinalysis, and bloodwork
  • Specific tests such as biopsy might also be needed
  • Treatment varies according to the severity and the underlying condition and might include specific medications, antibiotics, and surgical correction
  • In some severe cases, amputation of the penis and reconstruction of the urinary tract is necessary
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A closer look: Persistent Erection (Priapism and Paraphimosis) in Dogs

Priapism is uncommon in dogs. Paraphimosis is more common after manual semen collection, and rare after coitus.

Priapism is considered an emergency, especially if tissue death (necrosis) is present. Paraphimosis, while not life-threatening, requires prompt veterinary intervention, as the risk of severe edema and pain is high.

Possible causes

Priapism can also be idiopathic, meaning the cause cannot be determined.

Paraphimosis mostly happens after copulation or after manual semen collection.

Most commonly paraphimosis has a genetic component.

Risk factors

Prolonged extension of the penis has the potential to prevent passage of urine, which is a medical emergency.

Dogs used as breeding studs are at higher risk of persistent erection or penile extension from the prepuce, especially if semen is routinely extracted manually. A genetic component is suspected, so dogs with a history of persistent penile extension may pass the predisposition on to offspring.

Testing and diagnosis

The diagnostic process usually includes:

  • Medical history
  • Physical examination
  • Blood work
  • Urinalysis
  • Diagnostic imaging (x-ray, ultrasound)
  • Biopsy may also be necessary

Treatment varies depending on severity and the underlying condition. Treatment often starts with cleaning and lubricating the exposed penis. If this fails, treatment might include:

  • Surgery
  • Amputation of the penis
  • Urethrostomy
  • Antibiotics
  • Topical medications
  • Radiotherapy
  • Catheter placement and urine drainage
  • Anti-inflammatory medications
  • Blood pressure medications

Similar symptoms

Priapism can be easily mistaken for paraphimosis and vice versa.

Associated symptoms


Teri Ann Oursler, DVM - Writing for Veterinary Partner
Hannah Hollinger - Writing for Wag!
Autumn P. Davidson , DVM, MS, DACVIM - Writing for Merck Veterinary Manual
Autumn P. Davidson , DVM, MS, DACVIM - Writing for Merck Veterinary Manual
Michael M. Pavletic, DVM, DACVS - Writing for Standards of Care: Emergency and Critical Care Medicine

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