Canis ISSN: 2398-2942

Prostate: benign hyperplasia and hypertrophy

Synonym(s): BPH

Contributor(s): Prof Gary England, Sarah L Freeman

Introduction

  • Benign hyperplasia and hypertrophy is an age-related condition common in dogs of 5 years or older.
  • Testosterone is metabolised to 5-alpha-dihydrotestosterone (DHT) and long-term exposure to DHT causes enlargement of the prostate.
  • The condition is not seen in the castrated male.
  • Signs: many dogs are asymptomatic.
  • Early signs may include hemospermia with later hemorrhagic discharge at the penile tip not related to urination.
  • Pollakiuria (abnormally frequent urination) may be noted.
  • Defecatory tenesmus and constipation occur later.
  • Non-painful, symmetrical bilateral enlargement of the prostate.
  • Stranguria and dysuria are not common.
  • Diagnosis: history, clinical signs and ultrasound examination.
  • Treatment: surgical castration or hormonal therapy (eg 5-alpha-reductase inhibitors, progestogens, or GnRH agonists).
  • Prognosis: good.

Pathogenesis

Etiology

  • 5-alpha-dihydrotestosterone (DHT) stimulates glandular and cellular proliferation of the prostate.
  • Older intact dogs have long-term exposure to DHT.
  • OLder dogs secrete less testosterone and less DHT than younger dogs, but secrete more estradiol; estrogen sensitises the prostate to DHT so overall older dogs have greater hyperplasia and hypertrophy.

Specific

  • Long-term presence of the active metabolite of testosterone cause prostate hyperplasia and hypertrophy.

Pathophysiology

  • Increased cell numbers and glandular development causes a symmetrical enlargement of the gland.
  • The enlarged gland has increased vascularity and vascular leakage is common resulting in initial contamination of the first and third fractions of the ejaculate (hemospermia) with a later hemorrhagic discharge noted at the penile tip.
  • Gland enlargement may cause compression of prostatic ducts reading to prostatic fluid accumulation and cyst formation.
  • The enlarged gland may impinge on the rectum causing defecatory tenesmus and later rectal diverticula and perineal hernia.
  • Hyperplasia and hypertrophy may be seen concomitantly with:

Timecourse

  • Months to years.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Russo M, Vignoli M & England G C W (2012) Beta-mode and contrast-enhanced ultrasonographic findings in canine prostatic disorders. Reprod Domest Anim 47 (Suppl 6), 238-242 PubMed.
  • Vignoli M, Russo M, Catone G, Rossi F, Attansasi G, Terragni R, Saunders J, England G C W (2011) Assessment of vascular perfusion kinetic using contrast-enhanced ultrasound for the diagnosis of prostatic disease in dogs. Reprod Domest Anim 46 (2), 209-213 PubMed.
  • Albouy M, Sanquer A, Maynard L & Eun H (2008) Efficacies of osaterone and delmadinone in the treatment of benign prostatic hyperplasia in dogs. Vet Rec 163 (6), 179-183 PubMed.
  • Sirinarumitr K, Johnston S D et al (2001) Effects of finasteride on the size of the prostate gland and semen quality in dogs with benign prostatic hypertrophy. JAVMA 218 (8), 1275-1280 PubMed.

Other sources of information

  • Kustritz M V R (2010)How do I treat benign prostatic hypertrophy.In:Clinical Canine and Feline Reproduction Evidence-Based Answers. Iowa: Wiley-Blackwell. pp 173-175.


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