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826 Prostatic Enlargement (Noninfectious, Non-Neoplastic)

Medical treatment can act within weeks (see the hypothalamus and by inhibiting prostatic PROGNOSIS & OUTCOME
Chronic Treatment). 5-alpha-reductase. For BPH with or without cysts, the prognosis
VetBooks.ir Chronic Treatment terone analogs combine good efficacy for is excellent. Dogs not showing clinical signs
○ The clinical effects of synthetic proges-
may remain symptom free for months to
prostatic hyperplasia with only mild to
Reversible medical therapy should be considered
for breeding dogs or older dogs with significant
of BPH, and intraparenchymal prostatic cysts
anesthesia risks. These forms of therapy are safe moderate systemic antiandrogenic effects, years. Castration is curative of clinical signs
including decreased libido and fertility.
and practical, even for long-term treatment and ○ One injection of medroxyprogesterone will decrease in size.
for breeding dogs. Therapeutic response should acetate resulted in complete resolution
be evaluated, even with complete resolution of of clinical signs in 84% of dogs in 4-6 PEARLS & CONSIDERATIONS
clinical signs, because of the risk of concurrent weeks, and 68% remained asymptomatic
infection or neoplasia. Between 3 and 4 weeks for at least 10 months. Comments
after initiation of therapy, BPH should have • Deslorelin (Suprelorin, Virbac) is a • Young, valuable breeding dogs with prostatic
sufficiently regressed, and coexisting diseases gonadotropin-releasing hormone (GnRH) disease are more likely to be asymptomatic
are more likely to be detected. agonist available in an SQ sustained-release and should be regularly screened for prostatic
• Finasteride 0.1-0.5 mg/kg (maximum 5 mg/ implant. Administration induces down- disease by prostatic ultrasound and a semen
DOG) PO q 24h is a synthetic steroid that regulation of pituitary GnRH receptors evaluation.
inhibits prostatic type II 5-alpha-reductase, and subsequent complete suppression of • CPSE is a biomarker for BPH but is not
which blocks conversion of testosterone gonadotropins (luteinizing hormone [LH], clinically useful because it does not distin-
to DHT. follicle-stimulating hormone [FSH]) and guish BPH, bacterial prostatitis, or prostatic
○ This results in selective blockade of gonadal hormones (testosterone, estradiol). carcinoma.
prostatic androgen effects, prostatic ○ This product causes reversible but com- • Semen evaluation and freezing may be
atrophy, and decrease in prostatic volume plete nonselective chemical castration with performed during finasteride treatment and
of 50%-70% in 2-4 weeks. Clinical signs infertility and suppressed semen quality. does not interfere with fertility.
associated with BPH begin to resolve after Testicular and prostatic size reduction is
1 week of therapy, and most dogs are achieved reliably for at least 6-12 months. Prevention
asymptomatic within 4 weeks. Surgical castration
○ Prostatic DHT concentrations decrease, Nutrition/Diet
but serum testosterone concentrations An herbal supplement derived from the berry Technician Tips
remain unchanged. Dogs therefore of the saw palmetto plant reportedly improves • Counsel owners of young healthy breeding
maintain libido and fertility, and they urinary flow rates in men with BPH. However, dogs regarding the high incidence of BPH,
can be bred successfully. Semen volume use of this supplement for 3 months in dogs and discuss semen cryopreservation for
decreases without negative effect on semen with BPH did not reduce prostate size. valuable breeding stock.
quality. • Recommend annual prostate exams with
○ Treatment should be continued for 1-4 Behavior/Exercise breeding evaluations and B. canis screening.
months or longer. However, the prostate Exposure to estrous females may increase
will return to its original size in 4-8 weeks prostatic fluid secretions and exacerbate clinical Client Education
after discontinuing therapy. signs associated with BPH. • BPH should be considered a normal age-
• Osaterone acetate (Epostane, Virbac 0.25 related change in intact male dogs, and most
to 0.5 mg/kg PO q 24h) is a synthetic Drug Interactions dogs are asymptomatic. Symptoms associated
testosterone analog with antiandrogen and All progestogens can increase appetite, suppress with BPH occur mostly in advanced stages
progestogen effects. It blocks the absorption the adrenal axis, and increase susceptibility to and include lower urinary tract signs (e.g.,
of testosterone in the prostate and competi- insulin resistance and diabetes mellitus. hematuria, dysuria), gastrointestinal signs
tively inhibits prostatic DHT receptors. (e.g., tenesmus, obstipation), or reproductive
○ Osaterone decreases prostatic volume by Possible Complications signs (e.g., sanguineous preputial discharge,
approximately 27% after 1 week and 40% Complications associated with FNA of the hematospermia, infertility).
after 2 weeks. One-half of treated dogs prostate include periprostatic hemorrhage, • The goal of BPH treatment is to reduce
exhibit resolution of BPH clinical signs hematuria, dissemination of a concurrent prostatic size and thereby alleviate clinical
in 2 weeks and 83% in months. prostate infection, laceration of major blood signs and decrease the risk of complications
○ Because osaterone does not suppress vessels, urethral fistulation, orchitis, or inadver- (e.g., prostatitis, prostatic abscess). Treatment
testosterone production itself but only tent puncture of adjacent organs. Avoid FNA options involve surgical castration (perma-
its effect on the prostate, it should have before examining prostatic fluid obtained by nent) or medical management (reversible).
no effect on sperm quality and fertility. ejaculation or prostatic massage. Risk may
However, osaterone can decrease serum be increased in febrile animals or those with SUGGESTED READING
cortisol concentrations and may interfere leukocytosis. Kutzler M: Prostatic diseases. In Ettinger SJ, et al,
with ACTH response in hormonal testing editors: Textbook of veterinary internal medicine,
and induce adrenocortical insufficiency. Recommended Monitoring ed 8, St. Louis, 2017, Elsevier, pp 2031-2036.
• Synthetic progesterone analogs (medroxy- • Record prostate size for all male dogs (intact AUTHOR & EDITOR: Michelle A. Kutzler, DVM, PhD,
progesterone acetate 3-4 mg/kg SQ as and neutered) with each physical exam. DACT
necessary, megestrol acetate 0.5 mg/kg • If asymmetrically enlarged or enlargement
PO q 24h) exert antiandrogen activity is associated with clinical signs in an intact
by decreasing testosterone concentrations dog, perform transabdominal ultrasound to
through negative feedback at the level of rule out coexisting conditions.

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