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Prostate: benign hyperplasia and hypertrophy
Synonym(s): BPH
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.
Presenting signs
- Many dogs are asymptomatic but prostatic enlargement can be confirmed by rectal palpation.
- Early signs may include hemospermia identified at the time of semen collection.
- Classical presentations have a hemorrhagic discharge at the penile tip that is not related to urination.
- Defecatory tenesmus occurs later in the disease.
- Pollakiuria (abormally frequent urination) may be noted.
- The owner may report constipation.
- The condition may be associated with rectal diverticulae and perineal hernia.
- Stranguria and dysuria are not common.
Age predisposition
- Clinical disease seen most commonly in dog >5 years old (16% of dogs have histologic evidence of BPH by 2 years of age; 50% by 4-5 years of age).
Cost considerations
- Moderate expenses incurred in diagnostic makeup, eg radiography, ultrasonography, prostatic fluid collection, etc.
- Loss of breeding potential in stud dog.
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:
- Prostatic retention cyst Prostate: cyst
- Prostatic abscessation Prostate: abscessation.
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.