Sperm quality and selected biochemical parameters of seminal fluid in dogs with benign prostatic hyperplasia

Potential role of oxidative stress in pathogenesis of benign prostatic hyperplasia in male dogs

The pathogenesis of benign prostatic hyperplasia (BPH) in dogs is still not fully understood. Some studies suggest that oxidative stress may have a potential role in the pathogenesis of BPH in dogs. Age-related hormonal changes may activate a chronic inflammatory response in the prostate. This causes the generation of reactive oxygen species (ROS) and results in oxidative stress. Excessive production of ROS results in DNA damage and hyperplastic transformation of prostatic cells. The use of antioxidants for improvement of treatment outcomes for canine PBH has been discussed. Further research is needed on the importance of oxidative stress in the development of BPH in dogs and the usefulness of antioxidants in the supportive treatment of this condition.

Frozen-Thawed Sperm Analysis of Benign Prostatic Hyperplasia Dogs Treated With Finasteride

Benign Prostatic Hyperplasia (BPH) is a pathological condition that directly interferes with the reproductive potential of senile dogs, by leading to prostate enlargement and sperm injury, which in turn may compromise sperm freezeability. Moreover, albeit finasteride treatment reduces prostatic volume and blood supply and maintains seminal quality and testicular integrity, the effects of sperm samples submitted to cryopreservation after the finasteride treatment are still unknown. Thus, the aim of this study was to evaluate frozen-thawed semen of BPH dogs, as well as dogs subjected to BPH pharmacological treatment with finasteride. For such purpose, 20 dogs were previously selected and assigned to three experimental groups, according to BPH diagnosis and treatment with finasteride: Control (n = 9), BPH Group (n = 5) and BPH-Finasteride Group (n = 6). Semen was subjected to one-step cryopreservation protocol with tris-fructose-citric acid extender with 5% glycerol and thawed at 37°C for 30 sec. Fresh and post-thaw sperm samples were evaluated for macroscopic parameters, sperm concentration, sperm motility kinetics, sperm mitochondrial activity and potential, oxidative stress, plasmatic and acrosome membrane integrity, sperm DNA fragmentation and sperm binding test on perivitelic membrane of chicken egg yolk. Regarding fresh semen, BPH-Finasteride group had the lowest ejaculate visual aspect (opacity), higher frequency of sperm flagellar beating (BCF) and percentage of sperm with medium velocity. Control group had the highest percentage of sperm DNA integrity compared to BPH group. For the frozen-thawed semen, Control group presented the highest percentage of spermatozoa with high mitochondrial activity. However, the BPH-Finasteride group showed higher number of sperm bound to the perivitelline membrane of chicken egg yolk compared to the BPH Group. Conversely, BPH group had higher percentage of DNA damage. In conclusion, the ejaculate of BPH dogs has higher susceptibility to cryoinjury, whereas finasteride-treated dogs have increased spermatozoa functional performance, suggesting a promising use of BPH dogs as semen donors in sperm cryopreservation programs.

Prostatic fluid composition and semen quality in dogs with benign prostatic hyperplasia undergoing treatment with osaterone acetate

Benign prostatic hyperplasia (BPH) may alter prostatic fluid biochemical composition causing reduced fertility. Osaterone acetate (OA) is an androgen receptor antagonist marketed for treatment of canine BPH. Little information exists on effects of OA administration on biochemical composition of canine prostatic fluid and its role on fertility. The aim of this research was to study biochemical composition of prostatic fluid and its role on semen quality in dogs with BPH undergoing treatment with OA. Eight intact, 5-11-year-old dogs with benign prostatic hyperplasia were treated orally with OA at a dose of 0.25-0.5 mg/kg once daily for seven days. Prostatic volume, semen evaluation and a biochemical analysis of prostatic fluid were performed on the day before treatment (D0), D60, D120, D180 and D240. A significant reduction (57% and 61%) of prostatic volume was observed at D60 and D120, respectively, and a significant reduction (20%) of normal spermatozoa was observed at D60 coincident with a significant increase of sperm tail defects, which disappeared during the course of the treatment. Prostatic fluid composition did not vary during the OA treatment except for zinc (Zn²⁺ ) with a significant increase at D120 and D180 correlated with the return to normal sperm values. In conclusion, canine Zn²⁺ prostatic fluid concentrations decrease during development of BPH and return to normal during treatment with OA. Zn²⁺ is an important electrolyte for semen quality, suggesting that oral Zn²⁺ supplementation might be considered a treatment to improve semen quality.

Correlation of Prostatic Artery Blood Flow Assessed by Doppler Ultrasonography with Semen Characteristics in Beagle Dogs

Simple Summary

This study examined the blood flow parameters of the prostate artery before dog ejaculation assessed by pulsed-wave Doppler ultrasound (PwD) changes. The main objective of this study was to characterize the vascular parameters of the prostatic artery in beagle dogs and to explore the potential use of Doppler ultrasonography as a complementary method in dog stud selection. These findings report differences between blood flow parameters in cranial and caudal locations of the prostatic artery in comparison to subcapsular and parenchymal locations. There was a high positive correlation of peak systolic velocity with total volume and sperm concentration. In conclusion, estimation of the PwD parameters of the cranial prostatic artery may be useful in the breeding evaluation of dogs.

Abstract

Pulsed-wave Doppler ultrasonography (PwD) is a method used to rapidly and noninvasively assess blood flow dynamics of the canine prostate. Modifications in gland vascularization can affect seminal plasma production and consequently sperm quality. The aim of this study was to determine the normal blood flow parameters of the prostate artery in beagle dogs and to analyze the correlations between vascular flow and semen quality characteristics. PwD was performed on five beagle dogs (5–6 years) measuring vascular features in four different locations of the prostatic artery (cranial, subcapsular, parenchymal and caudal); the measured features were peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI). Ejaculates were obtained using digital manipulation and semen quality was evaluated by determining macroscopic (total volume, sperm-rich fraction volume, color and pH) and microscopic (sperm motility, morphology, viability and acrosome integrity) characteristics. The values of PSV, PI and RI in cranial and caudal prostatic arteries were significantly higher than in subcapsular and parenchymal arteries (p < 0.05). Moreover, a positive correlation of PSV value in the cranial region of the prostatic artery with total ejaculate volume (p < 0.01, r = 0.612) and sperm concentration (p < 0.01, r = 0.587) was determined. PI index was negatively correlated with sperm concentration (p < 0.01, r = −0.709). In conclusion, the results suggest that the prostatic artery blood flow parameters can affect macroscopic semen quality characteristics in healthy dogs.

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

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.

Clinical and spermatological findings in male dogs with acquired infertility: A retrospective analysis

A variety of causative factors of infertility in male dogs has been reported. In this study, the results of clinical examination and semen evaluation of 61 infertile stud dogs are described. Infertility was defined as conception failure of at least three matings with different bitches. The dogs, belonged to various breeds, were 4-8 years old and had a history of prior normal fertility. The dogs were subjected to clinical examination including ultrasonography of the prostate and testes. The semen was evaluated using CASA and microscopically morphology and live-dead spermatozoa. In all dogs, the semen parameters were outside the reference range, and mostly oligoastheno-teratozoospermia was found. There were also three cases of azoospermia. Thirty dogs showed no clinical abnormalities of the genital organ and no signs of systemic diseases, and testicular degeneration was assumed as the possible cause of infertility. In 20 dogs, BPH was diagnosed. In three dogs, infertility was associated with hypothyroidism. Three dogs had a history of babesiosis, and one dog prolonged ketoconazole treatment. One case each of chronic prostatitis, prostatic adenocarcinoma, epididymitis and retrograde ejaculation was diagnosed. The cause of acquired infertility could not be identified in almost half of the dogs. In other, infertility was often associated with prostate diseases.

Does finasteride treatment for benign prostatic hyperplasia influence sperm DNA integrity in dogs?

BACKGROUND

Benign prostatic hyperplasia (BPH) is one of the most common reproductive disorders in both male dogs and men. Finasteride, a synthetic inhibitor of the enzyme 5α-reductase, is widely used as medical treatment. Although sperm can be affected by both BPH and finasteride treatment, the direct influence on DNA integrity remains unclear. Thus, the aim of this study was to verify the direct effect of BPH and/or finasteride treatment on DNA integrity of dog spermatozoa. A 2 × 2 factorial experiment was designed with 20 male dogs assigned to 4 experimental groups: BPH Group (n = 5), BPH-Finasteride Group (n = 5), Non-BPH Finasteride-Treated Group (n = 5) and Non-BPH Untreated Group (n = 5). Sperm evaluation was performed monthly for 60 days after the start of finasteride therapy or BPH diagnosis (D0, D30 and D60). Sperm DNA integrity was analyzed through fragmentation susceptibility (toluidine blue staining and Sperm Chromatic Structure Assay - SCSA), direct evaluation of DNA fragmentation (Sperm Chromatin Dispersion Assay - SCDA) and sperm protamination (chromomycin A3).

RESULTS

Sperm DNA integrity was not affected by finasteride treatment. However, BPH dogs had higher susceptibility to sperm DNA acid denaturation (SCSA) compared to dogs not presenting BPH, as well as lower percentage of sperm with DNA integrity (toluidine blue staining).

CONCLUSION

In conclusion, benign prostatic hyperplasia causes post-testicular sperm DNA damage, albeit finasteride treatment itself does not directly influence sperm DNA integrity.

Changes in specific serum biomarkers during the induction of prostatic hyperplasia in dogs

BACKGROUND

Prostatic hyperplasia (PH) is one of the most important disorders in intact dogs. In this study, we aimed to induce PH experimentally using the combination of testosterone and estrogen and evaluate important factors associated with this disease.

RESULTS

The results showed that in the induction group, prostate volume and prostate specific antigen (PSA) concentration increased significantly on day 21 onwards compared to those of the control group. Canine prostatic specific esterase (CPSE) and dihydrotestosterone (DHT) concentrations increased significantly on day 42 onwards while the testosterone levels increased on day 63. In addition, prostatic acid phosphatase (PAP) concentration did not change significantly in the control and induction groups. Biochemistry profiles and hematologic factors were measured for monitoring the function of liver and kidney, and there were no adverse effects following the induction of PH.

CONCLUSIONS

It seems that testosterone and estrogen administration led to prostatic hyperplasia during 2 months. Investigating the size of the prostate, accompanied by prostate markers including CPSE, PSA, DHT, and testosterone, is helpful for the PH diagnosis. However, further studies should be carried out on PAP.

Freezing and storage effects on enzyme, electrolyte, and mineral compositions in canine prostatic fluid

BACKGROUND

There is a paucity of information about the storage stability of seminal plasma components in literature.

OBJECTIVES

This study investigates the potential effects of storage at -18.0°C on the enzyme activities and concentrations of selected electrolytes and minerals in canine prostatic fluid.

METHODS

Semen was obtained in fractions from ten male dogs, and the third ejaculate fraction was analyzed immediately after sampling and after storage at -18.0°C for 7 days. The following analytes were assessed: gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), sodium, potassium, total calcium, inorganic phosphate, magnesium, zinc, and copper.

RESULTS

Whereas electrolyte and mineral concentrations were not affected by freezing and 7 days of storage, effects on the enzyme activities were variable. ALP, AST, and LDH activities were significantly decreased (P < .05) in the post-thaw samples compared with the freshly prepared samples.

CONCLUSIONS

Because freezing and storage of seminal plasma at -18°C had an impact on the activity of some enzymes, analyses should be performed in fresh, not frozen samples.

Concentrations of minerals in the canine prostatic fluid

Current knowledge about the composition of the prostate fluid in healthy male dogs is limited and restricted to small case numbers. Furthermore, published data often vary significantly regarding sample processing and analytical methods. Therefore, we aimed to provide data on the composition of electrolytes and minerals in the canine prostatic fluid in a larger population (n = 30 dogs/samples) and to compare these results with the existing literature. Concentrations of sodium, potassium and copper analysed in our population were most consistent with those in the literature. Different to this, concentrations of total calcium, magnesium, zinc and inorganic phosphate varied. Whereas magnesium, zinc and inorganic phosphate seemed to depend on the analysis method, total calcium concentrations differed if centrifugation was performed or not. Our results clearly indicate a need for standardization of methods for analysis of seminal plasma components.

Evaluation of Canine Sperm and Management of Semen Disorders

Semen evaluation of the male dog is a critical step in any canine infertility work-up. Assessment of total sperm count, sperm viability, and sperm morphology are the mainstay of breeding soundness evaluation. Adjunct tests, such as ultrasonography and serum hormone levels, can aid in diagnosis. Pharmacologic treatments, dietary supplements, and management practices may help improve breeding success in subfertile dogs. This article discusses a clinically practical approach to assessing sperm abnormalities and fertility in male dogs.

A fast, low-cost and efficient method for the diagnosis of sperm DNA fragmentation in several species

Sperm DNA fragmentation is a condition that interferes directly in the reproductive efficiency. Currently, there are several methods for assessing the sperm DNA integrity, such as Alkaline Comet, TUNEL and Sperm Chromatin Structure Assay. However, many of these techniques are laborious and require high-precision equipment. Thus, the development of new techniques can optimize the evaluation of sperm DNA damage. Therefore, the aim of this study was to standardize the toluidine blue (TB) stain technique for the analysis of DNA fragmentation of dog, cat, bull, stallion and ram spermatozoa. For this purpose, we used six animals of each specie (n = 30), in reproductive age. Sperm was collected by different methods according to the particularities of each species, and such samples were divided into two aliquots: a sperm sample was kept at 5°C (considered as intact sperm DNA), and the remaining samples were submitted to the induction of DNA fragmentation by exposure to ultraviolet light for 4 hr. Samples were then mixed with the intact sample to obtain known and progressive proportions of sperm with fragmented DNA (0%, 25%, 50%, 75% and 100%). Semen smears were performed and subjected to staining with TB. Blue-stained spermatozoa were considered to have DNA fragmentation. We observed high linear regression coefficients between the expected proportion of damaged DNA and the results of TB for dog, cat, ram, bull and stallion samples. In conclusion, TB stain was considered a fast and effective technique for the study of spermatozoa DNA in several species.

Evaluation of biomarker canine-prostate specific arginine esterase (CPSE) for the diagnosis of benign prostatic hyperplasia

Background

Benign prostatic hyperplasia (BPH) is the most common canine prostatic disorder. Although most or even all intact male dogs may develop BPH by 5–8 years of age, many show no clinical signs. Taking into account the non-specific character of clinical and ultrasonographic findings, a new diagnostic approach has recently been proposed based on the augmentation of blood canine prostate-specific arginine esterase (CPSE) in hyperplasic dogs. The aim of the present study was to verify CPSE levels in negative controls and hyperplasic dogs, considering cytological findings as the reference method and taking into account the fact that controls were middle-aged intact dogs (median of 5.0 years), contrarily to previous studies carried out with very young control dogs.

Results

Significant differences of median CPSE levels were found between controls and hyperplasic dogs (29.1 versus 160.7 ng/mL, respectively); and significant positive correlations were found between median CPSE levels and age or prostatic volume (r = 0.549 and 0.448, respectively; p < 0.001). Sensitivity, specificity, positive and negative likelihood ratios put into evidence the good performance of the test. The agreement between methods was found to be very high, notably between CPSE levels and cytological results (Cohen’s kappa coefficients above 0.8).

Conclusions

Considering the results all together, measurement of CPSE is confirmed as a useful and accurate method and should be considered as an alternative or complementary tool to conventional methods for the diagnosis of BPH in middle-aged dogs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-0996-5) contains supplementary material, which is available to authorized users.