Changes in plasma testosterone and testicular transferrin concentration, testicular histology and semen quality after treatment of testosterone-depot plus PMSG to 3 dogs with asthenozoospermia

Three dogs diagnosed as having asthenozoospermia were given three intramuscular injections of 50 mg testosterone(T)-depot plus 250 IU pregnant mare serum gonadotropin (PMSG) at 2-week intervals, and their plasma T and testicular transferrin (Tf) concentrations, testicular histology, and semen quality were examined during the period of hormone therapy. Plasma T concentrations temporarily increased, and there was a slight improvement in spermatogenesis. Increased Tf concentrations suggested that Sertoli cell function in all three dogs was promoted by hormone treatment. The results showed that semen quality, especially the percentages of motile sperm and abnormal sperm, were improved between 1 and 5 weeks after the start of T-depot plus PMSG treatment.     

MEDROXYPROGESTERONE ACETATE AND REPRODUCTIVE PROCESSES IN MALE DOGS

The treatment of normal male dogs with a depot preparation of medroxyprogesterone acetate (4 mg/kg) for 7 weeks reduced peripheral testosterone levels by 58%. No effects on testicular size and consistency, semen quality or libido were found.     

Unilateral and Bilateral Vasectomy in the Dog: Alkaline Phosphatase as an Indicator of Tubular Patency

Contents The objective of this research was to use a model of unilateral and bilateral occlusion of the ductus deferens in the dog to study the use of alkaline phosphatase (AP) as an indicator of tubular patency. Seven healthy cross bred dogs weighing 10–15 kg BW with normal spermiogram and AP concentrations in semen were used. From each dog, three semen samples were obtained before (intact) and after right (unilateral) and left (bilateral) vasectomy. The AP concentrations were measured in duplicates by a colorimetric method in each of the three fractions (first, second (sperm-rich), third) of each ejaculate. In addition, a macroscopic and microscopic evaluation of each ejaculate was carried out to assure its quality. Data were analysed by least squares analysis of variance using SAS^®. In intact and unilateral vasectomized dogs, 96.6% of AP measured in semen corresponded to the second sperm-rich fraction whereas 1.53 and 1.83% corresponded to the first and third fractions respectively. Total AP concentrations (first and second and third fraction) in vasectomized dogs were lower than in intact animals (19.857 vs 2284.431 ± 4.347 UAL; p < 0.001). AP concentrations were much lower in bilateral than in unilateral vasectomized dogs (142 vs 39.572 ± 4.347 UL, p < 0.001). In summary, AP concentrations in semen can be used as an early indicator of unilateral or bilateral lack of patency of the epididymal and deferent ducts in the dog.     

Therapeutic effect of aromatase inhibitor in two azoospermic dogs with high plasma estradiol-17beta levels

Two azoospermic dogs with high plasma estradiol-17 beta (E(2)) levels were subcutaneously injected with an aromatase inhibitor (AI), 4-androstene-4-ol-3,17-dione, 2 mg every other day for 4 weeks. Before the AI treatment the plasma E(2) levels of the two dogs (21 and 22 pg/ml, respectively) were higher than those of 2 normal dogs (8.1 and 12.3 pg/ml), and they fell to 11-17 pg/ml between 1 and 4 weeks after the start of AI treatment. The plasma testosterone levels after the start of AI treatment had increased to 2.1-3.1 ng/ml. A small number of sperm were detected in the semen of the two dogs between 3 and 6 weeks after the start of AI treatment. These results indicate that the testicular function of infertile dogs with high plasma E(2) levels can be temporarily improved by AI therapy.     

Poor semen quality in Irish wolfhounds: A clinical, hormonal and spermatological study

On the basis of clinical observations, Irish wolfhounds were suspected as being subject to a relatively high incidence of soft testicular consistency and low semen quality. Thirty-seven Irish wolfhounds and 67 dogs of other breeds (control group) were therefore examined. Conventional andrological studies were performed in both groups, these included libido testing, palpation and measurement of testes and semen evaluation. Semen evaluation was performed both manually and by videomicrographic analysis. Testosterone concentrations were measured both before and after human chorionic gonadotropin challenge in the Irish wolfhounds. The Irish wolfhounds had lower libidos than the control group. More Irish wolfhounds (21-2 per cent) exhibited low semen quality than the control group (6-1 per cent). Soft testicular consistency occurred more frequently in Irish wolfhounds (25-7 per cent) than in the control group (10-5 per cent). In the control group, bodyweight correlated significantly with total sperm count. Serum testosterone concentration did not correlate with semen quality parameters.     

Effects of Short-term Hyper- and Hypoprolactinaemia on Hormones of the Pituitary, Gonad and -Thyroid Axis and on Semen Quality in Male Beagles

Effects of a short-term hyper- and hypoprolactinaemia on serum concentrations of LH, testosterone and semen quality in six male Beagles were investigated. Blood samples were collected at 3-day intervals for 12 weeks. The time span was divided into five 3-week periods: pre-treatment, metoclopramide (MCP) treatment (0.2 mg/kg orally three times daily), cabergoline (CAB) treatment (5 μg/kg orally once daily), post-treatment 1 and post-treatment 2. In the latter, only semen characteristics were evaluated. Semen parameters were analyzed once per week during the whole 15-week investigation time. At the end of each period, the effects of a single intravenous injection of thyrotropin-releasing hormone (TRH; 10 μg/kg) on the secretion of prolactin (PRL), LH, testosterone, thyroid-stimulating hormone and thyroxine (T4) were investigated. Pre-treatment serum PRL concentration increased under MCP (p < 0.05), followed by a decrease under CAB administration (p < 0.05). Luteinizing hormone and testosterone concentrations were not affected. Except for straight-line sperm velocity, semen quality did not differ between collection periods. A single iv TRH injection induced a significant PRL increase at 20 min in all experimental periods except during CAB treatment. Luteinizing hormone and testosterone did not show clear TRH-related changes. Basic T4 levels were significantly reduced after CAB treatment (p < 0.05). The results of the present study demonstrate that MCP-induced short-term hyperprolactinaemia in male beagles does not seriously affect the hypothalamo-pituitary axis and semen quality.     

Tris-Lecithin Extender Supplemented With Antioxidant Catalase for Chilling of Canine Semen

The aims were to evaluate the suitability of a non-commercial TRIS-lecithin (LC) extender and the effect of different concentrations of catalase (CAT) on motility, capacitation status (Chlortetracycline-assay) and zona pellucida (ZP) binding capacity of canine spermatozoa stored at +5°C for 4 days. The sperm-rich fractions of the ejaculates of four stud dogs were divided into four aliquots. After centrifugation, sperm pellets were diluted (200 × 10⁶ sperm/ml) in TRIS buffer, citric acid, fructose, antibiotics, supplemented with 20% egg yolk (TRIS-EY) or 0.04% soybean lecithin (TRIS-LC) with CAT (150 or 450 UI/ml) or without CAT, and then preserved at 5°C for 4 days. The results showed that LC is a valid alternative to EY for chilling canine semen, as similar rates of motility, number of uncapacitated spermatozoa and of spermatozoa binding the oocyte ZP were obtained in semen chilled in TRIS-LC or TRIS-EY. Different concentrations of CAT in a TRIS-LC based extender did not improve the quality of semen after chilling. However, a concentration of 150 UI/ml CAT resulted in an increased number of spermatozoa bound to the oocyte ZP, after 4 days of chilling when compared to semen chilled with TRIS-EY and TRIS-LC. In conclusion, an animal protein-free extender with soybean LC, as a replacement of EY, is suitable for 4 days chilling of canine spermatozoa, but the addition of CAT does not improve general semen quality except for a slight effect on sperm-ZP binding.     

Therapeutic effects of vitamin E supplementation in 4 dogs with poor semen quality and low superoxide dismutase activity in seminal plasma

Four dogs with poor semen quality, low seminal plasma superoxide dismutase (SOD) activity and low blood plasma testosterone (T) levels were orally administered one vitamin E tablet containing 50 mg α-tocopheryl acetate per dog daily for 4 weeks. The mean values of semen quality were temporarily improved after the start of vitamin E treatment and the values of 4, and 5 weeks after that were significantly different from those before the treatment (P<0.05–0.001). The mean blood plasma T and seminal plasma SOD activity values slightly increased in the 4 dogs after the treatment. The results of the present study indicate that poor semen quality in dogs with low seminal plasma SOD can be improved by vitamin E treatment.     

Effects of finasteride on size of the prostate gland and semen quality in dogs with benign prostatic hypertrophy

OBJECTIVE: To determine the effect of the 5alpha-reductase inhibitor finasteride on prostatic diameter and volume, semen quality, and serum dihydrotestosterone (DHT) and testosterone concentrations in dogs with spontaneous benign prostatic hypertrophy (BPH). DESIGN: Double-blind placebo-controlled trial. ANIMALS: 9 dogs with BPH. PROCEDURE: Five dogs were treated with finasteride for 16 weeks (0.1 to 0.5 mg/kg [0.05 to 0.23 mg/lb] of body weight, PO, q 24 h); the other 4 received a placebo. Prostatic diameter, measured radiographically, prostatic volume, measured ultrasonographically, semen quality, and serum DHT and testosterone concentrations were evaluated before and during treatment. After receiving the placebo for 16 weeks, the 4 control dogs were treated with finasteride for 16 weeks, and evaluations were repeated. RESULTS: Finasteride significantly decreased prostatic diameter (mean percentage decrease, 20%), prostatic volume (mean percentage decrease, 43%), and serum DHT concentration (mean percentage decrease, 58%). Finasteride decreased semen volume but did not adversely effect semen quality or serum testosterone concentration. No adverse effects were reported by owners of dogs in the study. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that finasteride can be used to reduce prostatic size in dogs with BPH without adversely affecting semen quality or serum testosterone concentration.     

Integrated Evaluation of Scrotal Temperature and Testosteronemia after GnRH Administration in Young Bulls with Low Semen Production

The aim of this study was to determine the suitability of thermographic monitoring of scrotal surface temperature (SST) as a method to monitor testicular function. Yearling bulls (n = 23) with low semen production were selected. Scrotal surface temperature and serum testosterone (T) concentrations were evaluated before and after administration of 10.5 μg buserelin acetate IV. Thermographic images of scrotum were recorded at 0, 15, 30, 45 and 60 min post‐GnRH, while blood sampling was only performed at 60 min post‐GnRH. Bulls were divided in two groups: LowTemp bulls (n = 10) had a decreased SST at 60 min; HighTemp bulls (n = 13) had an increased SST. After 60 min, LowTemp bulls had higher T concentrations compared to HighTemp bulls: 14.32 ng/ml ± 0.53 vs 10.30 ± 1.37 ng/ml (mean ± SEM; p < 0.05), respectively. Reproductive performances in both groups improved after GnRH administration, resulting in an increased number of inseminating doses from each collection, which was higher in LowTemp bulls. Pearson correlation test showed a negative relationship between T and SST (r = ?0.554). In conclusion, a decreased scrotal surface temperature 60 min after GnRH treatment was associated with improved semen production.     

Azoospermia in two Labrador retrievers

Azoospermia is described in two sibling Labrador Retriever dogs. Clinical investigations following failure to sire pups after normal matings revealed testicular hypoplasia and degeneration. Sperm were absent on repeated ejaculate examination in both dogs. Histopathological examination of testicular needle aspirate biopsy and whole testicle of the first dog displayed an absence of spermatids and spermatocytes. Seminiferous tubules containing Sertoli cells with or without primary spermatogonia were present in the second dog. Peritubular lymphocyte accumulation was also present in both dogs. The dogs had been conceived using frozen-thawed semen.     

Effect of supplementation with the reduced form of coenzyme Q10 on semen quality and antioxidant status in dogs with poor semen quality: Three case studies

Oxidative stress owing to an imbalance between reactive oxygen species and antioxidants, such as coenzyme Q10 (CoQ10), is a major contributor to male infertility. We investigated the effects of the reduced form of CoQ10 (ubiquinol) supplementation on semen quality in dogs with poor semen quality. Three dogs received 100 mg of ubiquinol orally once daily for 12 weeks. Semen quality, serum testosterone, and seminal plasma superoxide dismutase (SOD) activity were examined at 2-week intervals from 2 weeks before ubiquinol supplementation to 4 weeks after the treatment. Ubiquinol improved sperm motility, reduced morphologically abnormal sperm, and increased seminal plasma SOD activity; however, it had no effect on testosterone level, semen volume, and sperm number. Ubiquinol supplementation could be used as a non-endocrine therapy for infertile dogs.     

Influence of Ascorbic Acid and Glutathione Antioxidants on Frozen-Thawed Canine Semen

Poor sperm viability post-thaw has resulted in constant research into methods of cryopreservation of canine semen. One factor that may be involved in poor viability is sperm oxidative stress caused by excessive formation of reactive oxygen species. The present study was performed in order to evaluate the effect of different concentrations of ascorbic acid (AA) and glutathione (Glu) added to an extender for the freeze-thawing of dog sperm. Semen from five mature dogs was collected and frozen in two studies. Prior to and after freezing, sperm motility, morphology and membrane status were examined. In addition, sperm motility was examined up to 120 min after thawing to evaluate thermo-resistance. In study I, semen was collected twice from each dog. On both occasions, semen was divided into three aliquots: control, Glu 1 m m and Glu 5 m m . In study II, semen was collected twice and divided into three aliquots; control, AA 50 μ m and AA 250 μ m . Initial sperm motility was significantly higher in sperm diluted with AA 50 μ m ; sperm longevity, however, measured by a thermal-resistance test (TRT), was higher for Glu treatments. Higher concentration of Glu produced significant improvement in TRT and membrane status, whereas higher concentration of AA had a negative impact in sperm longevity. Antioxidant supplementation to semen freezing extenders improved semen quality post-thaw. Moreover, Glu had the most beneficial effect when supplemented at 5 m m .     

Effect of Daily Food Supplementation with Essential Fatty Acids on Canine Semen Quality

Polyunsaturated fatty acids are important membrane components that influence membrane integrity and fluidity. In the present study, the effect of oral supplementation for 60 days with essential fatty acids (omega 3, 6 and 9) and vitamin E on canine semen quality was evaluated. Sixteen dogs were selected for the experiment; eight were used as the control group and eight received the fatty acid supplemented diet for 60 days. Semen samples were taken every 15 days during the entire experimental period and were analyzed for volume (ml), motility (%), vigour (0–5), concentration (×10⁶/ml), morphology of spermatozoa (%), plasma membrane integrity (%; using the hyposmotic swelling test) and thermoresistance (motility and vigour after 4 h at 38°C). We concluded that, daily supplementation with omega 3, omega 6 and omega 9 fatty acids, together with vitamin E, for a period of 60 days, significantly increased the semen volume of the treated group after 15 days of supplementation; the vigour and concentration of spermatozoa were superior after the first month of supplementation, while the percentage of morphologically abnormal spermatozoa decreased and the cells were protected against thermal stress.     

Effects of vincristine treatment on semen quality in a dog with a transmissible venereal tumour

The effect of vincristine treatment on semen parameters in a male boxer with a genital transmissible venereal tumour are described. The dog was treated with vincristine intravenously at 0.5 to 0.7 mg/m2 body surface area per week for six weeks until complete regression of the tumour occurred. Semen samples were collected before each application and then at weeks 10, 12, 17, 21 and 23 after the start of therapy. There were no alterations in libido or in testicular size and consistency either during or after treatment. Total sperm count decreased to abnormally low values during weeks 4 and 5, and then began to increase up to pretreatment values. No significant alterations in the other semen parameters were found during the study period.     

High plasma estradiol-17beta levels in dogs with benign prostatic hyperplasia and azoospermia

The semen quality of 22 dogs (4 to 7 years old) with benign prostatic hyperplasia (BPH) was examined at the hospital of our university, and 4 of the 22 BPH dogs were diagnosed as azoospermic. The mean peripheral plasma estradiol-17beta (E2) level (17.3 pg/ml) of the 18 BPH dogs with spermatogenic function was higher than that of 5 normal male dogs and their mean T level (1.7 ng/ml) was lower. The mean E2 level (27.3 pg/ml) of the 4 BPH dogs with azoospermia was significantly higher than the value in the BPH dogs with spermatogenic function (P<0.01), and the mean T level (1.1 ng/ml) was significantly lower (P<0.05). Five normal male dogs were given 10 intramuscular injections of estradiol benzoate (E2B) 5 microg/kg, at 3-day intervals to investigate the relationship between high plasma E2 levels and the cause of the BPH and azoospermia. Their testes and prostates were measured and biopsied both before and 30 days after the start of E2B injections. At 30 days after the start of the E2B injections, the mean peripheral plasma T levels had decreased by half, and the mean testicular volume had decreased to 88% of original volume. The numbers of spermatocytes, spermatids, and spermatozoa in the seminiferous tubules of all of the dogs were significantly lower (P<0.05, 0.01). In addition, the mean prostatic volume increased to 130%, the mean height of the glandular epithelium decreased, and the glandular lumen became increased in diameter. These findings indicate that both BPH and serious spermatogenic dysfunction may be simultaneously induced by protracted high plasma E2 levels in dogs.     

Influence of different anaesthetic protocols over the sperm quality on the fresh,chilled (4°C) and frozen‐thawed epididymal sperm samples in domestic dogs

This study assessed the influence of three different anaesthetic protocols on semen quality obtained from the epididymis. Sixty male dogs undergoing to routine sterilization were assigned to three anaesthetic protocols: thiopental group (TG, n = 20), propofol group (PG, n = 20) and ketamine–dexmedetomidine group (KDG, n = 20). Immediately after orchidectomy, the cauda epididymides and vas deferent ducts were isolated and then a retrograde flushing was performed to collect spermatozoa. In experiment 1, after the initial evaluation of the semen (sperm concentration, sperm motility and the percentages of live spermatozoa, abnormal spermatozoa and acrosome membrane integrity), semen samples were diluted in Tris‐glucose‐egg yolk extender and chilled for 48 hr, and the sperm motility was assessed at 6, 24 and 48 hr. In experiment 2, semen samples were diluted in Tris‐glucose‐egg yolk extender and chilled for 24 hr, and then samples were frozen in two extenders with different glycerol concentrations, to reach a final concentration of 50–100 × 10⁶ spermatozoa ml^?1, 20% egg yolk, 0.5% Equex and 4% and 5% glycerol, respectively. Mean values of total sperm concentration, sperm viability and the percentages of intact acrosome and abnormal spermatozoa were not significantly different between experimental groups, and therefore, the anaesthetic protocols assessed did not affect sperm parameters mentioned above. However, our study confirmed a detrimental effect of the use of thiopental (TG) over the total sperm motility (p < 0.05) and progressive sperm motility (p < 0.05) of the fresh and chilled epididymal sperm samples. The anaesthetic protocols including the application of propofol or ketamine–dexmedetomidine can be used to recover sperm in domestic canids without significant changes in sperm quality compared when semen is collected routinely and these techniques could be applicable to endangered wild canids.     

Testicular fine needle aspiration cytology as a diagnostic tool in dog infertility

The results of testicular aspirate cytology taken from clinical patients with a history of infertility were compared with the clinical and histological findings. Azoospermia was the most common and the most rewarding indication for the examination. Samples were also taken from cases with suspected testicular tumours, orchitis, epididymitis, severe oligo- and teratozoospermia, lack of libido and unilateral testicular atrophy. Histological and cytological findings were found to correlate well. Identification of cell types from normal germinal epithelium was relatively easy. No Immediate adverse effects of aspiration were noted. Five normospermic dogs were monitored for two to six months after aspiration, and there were no marked deleterious effects on testicular consistency, testicular histology or semen characteristics. Testicular cytology obtained by fine needle aspiration may, at least to some extent, be used to assist clinical diagnosis, especially In azoospermlc dogs and dogs with palpable changes of testicular tissue.     

Testicular Measurements and Daily Sperm Output of Tori and Estonian Breed Stallions

Evaluation of testicular measurements and daily sperm output (DSO) yields valuable information for predicting the reproductive capacity of stallions. The present study evaluated testicular measurements (height, length, width and circumference) and DSO of eight Tori and eight Estonian breed stallions. One ejaculate of semen was collected daily for 10 subsequent days from each stallion. The gel‐free volume of semen was measured with a graduated glass cylinder and the sperm concentration was assessed with a Chorjajev chamber. The volume of gel‐free fraction was multiplied by the sperm concentration to give the total number of spermatozoa (TSN). The DSO was calculated as mean TSN of collection on days 8–10 in Tori breed stallions and on days 4–10 in Estonian breed stallions. The DSO of Tori breed stallions was 12.9 × 10⁹ spermatozoa and of Estonian breed stallions 4.5 × 10⁹ spermatozoa (p < 0.001). Testicular measurements (in cm) 1 day after the last semen collection were as follows: left testis– height 7.3, length 10.4 and width 7.3 in Tori breed stallions, and 5.9, 8.1 and 5.9, respectively, in Estonian breed stallions; right testis– height 7.4, length 10.6 and width 7.4 in Tori breed stallions, and 5.5, 7.4 and 5.3, respectively, in Estonian breed stallions. All these testicular measurements were significantly smaller in Estonian than in Tori breed stallions (p < 0.001). Testicular circumference was 45.4 and 35.4 cm in Tori and Estonian breed stallions, respectively (p < 0.001). The testicular circumference was correlated with DSO in both Estonian (p < 0.05) and Tori breed stallions (p = 0.071). The results give us valuable information on the reproductive capacity of Tori and Estonian breed stallions.     

Fertilizing Capacity of Frozen Epididymal Sperm Collected from Dogs

The collection of epididymal sperm may be a valuable tool for canine reproduction especially since it can enable collection of cells after death of a valuable dog. The aim of the present study was to evaluate the viability of epididymal sperm after freeze-thawing. Epididymides were obtained from four adult dogs by elective orchiectomy. The caudal portion of the epididymides and part of the deferential ducts were squeezed by means of an anatomic clamp into a Petri dish containing either 0.9% saline solution (Group 1) or Ringer solution without lactate (Group 2). Samples were centrifuged at 800 ×  g for 10 min, the supernatant was removed and the pellet was diluted in one step with a Tris/citric acid/OEP (Orvus Es Paste) extender containing 7% glycerol and subjected to semen freezing. Oocytes were obtained from canine ovaries, after ovariohysterectomy. Only oocytes that were approximately 100 μm in diameter, with a dark ooplasm surrounded by three- or four-well formed cumulus cell layers were used for sperm testing. Frozen semen samples were thawed in a water bath at 70°C for 8 s and analysed at room temperature for sperm motility and velocity. Oocytes were incubated with spermatozoa in humidified atmosphere containing 5% CO₂ at 38°C for 18 h. Morphological and functional characteristics of spermatozoa were similar in both groups. However, the percentage of sperm cells bound to oocytes was significantly higher in Group 2 than in Group 1. This result suggests that the Ringer solution without lactate was a more suitable medium for collecting epididymal canine sperm than 0.9% saline.