Impact of Canine BPH on Semen Quality: Clinical Implications and Therapeutic Insight

Benign prostatic hyperplasia (BPH) in dogs extends beyond structural enlargement of the prostate and has significant implications for reproductive health. In breeding dogs, the condition directly influences semen quality through alterations in the prostatic environment. Understanding these changes is essential for clinicians managing infertility cases associated with prostatic disorders. 

Prostatic Changes and Their Effect on Seminal Environment 

The prostate contributes a substantial portion of seminal plasma, and any alteration in its structure or function can directly affect spermatozoa. In BPH, increased cellular activity and hormonal imbalance lead to the accumulation of reactive oxygen species, resulting in oxidative stress^1,2. This imbalance is characterized by reduced antioxidant defenses within the prostatic environment, creating conditions that are detrimental to sperm health. 

The altered biochemical composition of prostatic fluid exposes sperm cells to oxidative damage, affecting their structural integrity and functional capacity¹. Since spermatozoa are particularly sensitive to oxidative stress, even subtle changes in the prostatic milieu can lead to significant declines in semen quality. 

Clinical Evidence of Fertility Impairment 

BPH is strongly associated with subfertility and infertility in dogs, particularly those used for breeding. Studies have reported that 32.8% of infertile dogs are diagnosed with BPH, highlighting its clinical significance in reproductive practice. The condition contributes to increased DNA fragmentation within sperm cells, as well as a higher incidence of morphological abnormalities¹. 

These changes are directly linked to the oxidative status of the hyperplastic prostate, where excessive reactive oxygen species disrupt normal sperm function¹. The continuous exposure of spermatozoa to this altered environment further exacerbates damage, reducing their viability and fertilizing potential. 

Influence of Pharmacological Treatments on Semen Quality 

Finasteride has been shown to have minimal adverse effects on semen quality. Studies indicate that parameters such as sperm motility, morphology, and viability remain largely unchanged during treatment. Although a reduction in semen volume has been observed, this does not significantly affect total sperm counts. Additionally, finasteride has been associated with improved DNA integrity and enhanced sperm binding capacity in cryopreserved semen, suggesting potential benefits in certain reproductive contexts^1,3. 

Osaterone acetate, while effective in reducing prostate size and alleviating clinical signs, has been associated with transient alterations in semen quality. Changes include a temporary decrease in motility and an increase in morphological defects, particularly affecting the tail region^1,4. These effects are generally reversible, with semen parameters returning to baseline levels over time. 

GnRH antagonists, such as acyline, have a more pronounced impact on reproductive function. Studies have reported significant reductions in sperm concentration and motility, along with an increase in morphologically abnormal sperm¹. In some cases, aspermia has been observed during treatment, indicating a substantial suppression of spermatogenesis. 

Tamoxifen also negatively affects semen quality, leading to reductions in ejaculate volume, sperm count, and motility, as well as alterations in sperm morphology. These effects extend beyond the treatment period, further limiting its suitability in breeding dogs¹. 

In contrast, anastrazole has demonstrated a favorable profile, producing significant reductions in prostate volume without affecting semen quality or reproductive parameters¹. However, the available evidence is limited, and further studies are needed to confirm these findings. 

Conclusion 

Canine BPH significantly impacts semen quality through mechanisms involving oxidative stress and hormonal imbalance. The condition alters the prostatic environment, leading to DNA damage and reduced sperm function. While several pharmacological treatments are available, their effects on reproductive parameters vary. Finasteride remains a suitable option for preserving semen quality, whereas other therapies require careful consideration. A comprehensive approach that integrates prostatic and reproductive assessments is essential for effective management in breeding dogs.  

References:  

1. Posastiuc FP, Constantin NT, Domain G, Soom AV, Diaconescu AI, Codreanu MD. A systematic review of medical treatments for benign prostatic hyperplasia in dogs: Evaluating strategies for reproductive function preservation. Veterinary sciences. 2025 Jan 19;12(1):70. https://doi.org/10.3390/vetsci12010070 

2. Domoslawska A, Zdunczyk S, Bielecka A, Kankofer M. The effect of benign prostatic hyperplasia on total antioxidant capacity and protein peroxidation in canine prostatic fluid and spermatozoa. Polish journal of veterinary sciences. 2023;26(4). https://agro.icm.edu.pl/agro/element/bwmeta1.element.agro-423d3abd-6a18-484c-a574-f45746ae2b9d/c/14___Domoslawska.pdf 

3. Flores RB, Angrimani DD, Brito MM, Almeida LL, Lopes JV, Losano JD, Vannucchi CI. Frozen-Thawed Sperm Analysis of Benign Prostatic Hyperplasia Dogs Treated With Finasteride. Frontiers in veterinary science. 2022 Jun 30;9:901943. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.901943/full 
4. Niżański W, Eberhardt M, Ochota M, Fontaine C, Levy X, Pasikowska J. A comparative study of the effects of osaterone acetate and deslorelin acetate on sperm kinematics and morpho-functional parameters in dogs. Animals. 2022 Jun 15;12(12):1548. https://www.mdpi.com/2076-2615/12/12/1548