Reproductive and endocrinological effects of Benign Prostatic Hyperplasia and finasteride therapy in dogs

Abstract

Benign prostatic hyperplasia (BPH) is one of the most important reproductive disorders in aging dogs. Therapeutic measures include orchiectomy and pharmacological treatment, leading to reduction of prostate volume and clinical signs. One of the most common drugs used in BPH treatment is finasteride, but data regarding its possible side effects are scarce. Thus, the aim of this study was to evaluate the effects of BPH and short-term (2 months) finasteride therapy on clinical, endocrinological, and reproductive parameters in dogs. Dogs were allocated into four experimental groups: Non-affected (n = 5), BPH (n = 5), Non-Affected-Finasteride (n = 5) and BPH-Finasteride (n = 5) groups. Dogs were evaluated monthly during 2 months by a complete breeding soundness examination, B-mode ultrasound and Doppler ultrasonography of the testicular artery, hormonal profile (testosterone, estrogen and dihydrotestosterone) and oxidative profile of the prostatic fluid. After 2 months, dogs were gonadectomized and testicles were subjected to histologic analysis. Finasteride treatment reduced dihydrotestosterone concentrations, without negative influence on semen quality and also reverted testicular hemodynamics changes of BPH. On the other hand, BPH was accompanied by significant changes in testosterone and estrogen concentrations and semen quality, mainly related to sperm kinetics alterations. In conclusion, BPH dogs have important hormonal and sperm alterations, however, short-term finasteride treatment (2 months) was able to reduce overall effects of BPH, thus representing a method of therapy for BPH treatment.

Figure 1

(A) Estrogen (pg/mL) concentration in Non-affected and BPH dogs. (B) Dihydrotestosterone (pg/mL) concentration in Non-treated and Finasteride-treated dogs. (C) Testosterone concentration (ng/mL) of Non-affected, BPH, Non-treated and Finasteride-treated dogs. *Indicate significant difference (P < 0.05). **Indicate significant difference between Non-affected and Non-affected-Finasteride treated dogs (P < 0.05).

Figure 2

(A) Fast sperm velocity (%), (B) sperm beat cross-frequency (Hz) and (C) slow sperm velocity (%) in Non-affected and BPH dogs. *Indicate significant difference (P < 0.05).

Figure 3

(A) Sperm count (sperm/mL) and (B) minor sperm defects (%) in Non-affected and BPH dogs. *Indicate significant difference (P < 0.05).

Figure 4

(A) Pulsatility index (PI) and (B) time average maximum velocity (TAMAX) in Non-treated and Finasteride-treated dogs. *Indicate significant difference (P < 0.05).