Due to the increased attention that pet-owners devote to their animals and to the improved veterinary care, investigations regarding methods to early detect prostatic disorders that might affect canine life quality have been performed. Canine prostate specific esterase (CPSE) concentration was reported to be higher in dogs suffering from prostatic diseases. This study aimed to estimate the CPSE threshold as a biomarker to early identify prostatic diseases in asymptomatic dogs. The ultrasonographic examination of the prostate was performed in 19 dogs (6-40 kg; 1-5 years) with no symptoms of prostatic diseases. Dogs were grouped according to the presence (Group A) or absence (Group B) of prostatic disorders at the ultrasound (altered appearance, the presence of cysts or irregular borders). For each dog, a venous blood sample was collected to measure serum CPSE and the ratio between calculated and normal expected prostatic volume was assessed for each dog. The CPSE data were statistically analysed (t test, p < .05), and the CPSE threshold in blood serum between groups was calculated by ROC. In 11 dogs, ultrasonography showed signs of prostatic abnormalities (Group A, 2-5 years), while no signs were detected in eight dogs (Group B, 1-3 years). The calculated/estimated volume ratio resulted greater than 1.5 in Group A dogs. The CPSE was statistically different between groups (p < .0001): higher in Group A (mean = 184.9, SD = 126 ng/ml) than in Group B (38.9 ± 22.1 ng/ml). The cut-off CPSE threshold was 52.3 ng/ml (ROC, AUC = 0.974, SE 95.6%, SP 89.2%). This study suggests that CPSE serum concentration higher than 50 ng/ml in asymptomatic dogs is associated with ultrasonographic alterations and increased the prostatic size (volume by 1.5 times greater than the normal size). As the onset of prostatic disorders often remains asymptomatic, the rapid assessment of CPSE could be suitable for selecting preventively those animals that would require further accurate evaluation.

BackgroundCanine overpopulation is a global issue with serious health and welfare implications. Nonsurgical methods of sterilization could yield positive impacts on this problem, but no long-term data on such methods are available. The objective of the current investigation was to determine the effects of intratesticular injections of calcium chloride dihydrate (CaCl2) in saline in dogs over a one year period. Five concentrations (0%, 10%, 20%, 30%, 60%) of CaCl2 in saline were administered via intratesticular injection to groups of 10 dogs each. Total sperm count and motility, blood levels of testosterone, and side effects were examined at 0, 2, 6, and 12 months post-injection (PI). Testicular size and semen volume were examined at 0 and 12 months PI.ResultsTotal sperm count, semen volume and testosterone showed significant dose-dependent decreases upon treatment with 10%-60% CaCl2 compared with either the control group (0% CaCl2) or baseline for each treatment group. Azoospermia was achieved for at least 12 months PI in 60% and 80% of treated dogs after administration of a 10% and 20% CaCl2, respectively. Treatment with 30% or 60% CaCl2 resulted in azoospermia in 100% of dogs, but more side effects were observed, while no side effects were noticed at lower doses. For each treatment group, testosterone levels had decreased an average of 35%-70% at 6 months following treatment. However, testosterone levels rebounded by the 12-month time point in all groups except the highest dosage group (60% CaCl2), which remained at the low end of physiological range throughout the study. Sperm motility dropped to zero or near zero in all dogs treated with CaCl2. Testicular size was significantly smaller at 12 months PI for all groups when compared to baseline.ConclusionsThis first long-term study confirms reports of the efficacy of CaCl2 sterilization. However, at dosages free of adverse events, calcium chloride in saline may not provide permanent sterilization as previously believed. Future work should explore optimized solvents to increase the permanence of the well-tolerated 20% formulation.

Sub-fertility represents a common challenge in canine reproduction. Different protocols, supplementing daily given quantities of micronutrients, were investigated to improve poor sperm concentration and/or function, which represent breeding major constraining factors in the canine species. Little information is available for dogs concerning the effect of a daily supplementation with a complex of vitamin E, zinc, selenium, folic acid, and n-3 polyunsaturated fatty acids (PUFA) on semen quality. Thus, the present study investigated this effect on semen motility and sperm membrane properties. Serial semen analyses from fourteen healthy normospermic dogs, fed with the same commercial diet, were performed on Days 0 (T0), 30 (T30), 60 (T60), and 90 (T90). Seven dogs were randomly included in the treatment (T) group, receiving a supplementation of vitamin E, zinc, selenium, folic acid, n-3 PUFA; and seven other subjects composed the control (C) group. Total Sperm Count (TSC), Computer-Assisted Sperm Analysis (CASA) indexes, mortality, and functional membrane integrity were assessed. The ANOVA compared results between groups and sampling times (p < 0.05). From T60, the supplementation significantly improved TSC, progressive motility, functional membrane integrity, and decreased mortality. Present results lead us to consider ameliorative effects of a two-month healthy diet supplementation on canine spermatozoa. The positive effects of the described balanced integration of micronutrients on sperm motility and prevention of oxidative stress should be considered, especially when decreased seminal parameters may result from inadequate intake, reduced absorption, increased losses or demand, or to attenuate the impact of age.

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The development of fertilizing ability in sperm cells is associated with changes in the plasma membrane. However, to date the exact nature of sequentially activated primary receptors and channels and the signal transduction pathways derived from these remains elusive. We analyzed the expression and localization of the m-opioid receptor in equine spermatozoa. A transcript corresponding to the third extracellular loop that selectively binds m agonists was amplified, sequenced and compared with the known sequences in humans, rats and cattle. The amplification product showed a high degree of nucleotide conservation. By immunofluorescence, m-opioid receptor labeling was found on the sperm head and on the tail and disappeared in the acrosomal region of acrosome-reacted sperm cells. Immunoblotting revealed two bands of 50 and 65 kDa. Effects of the opioid antagonist naloxone on motility and on viability and capacitation/acrosome reaction were investigated by computerassisted sperm analysis and Hoechst 33258/chlortetracycline (H258/CTC) staining. Progressive motility was significantly reduced after 3 h incubation in 10 23 M naloxone (P < 0.05), whereas it increased significantly after 5 h in 10 28 M naloxone (P < 0.05). Sperm velocity at 5 h was significantly reduced by the addition of 10 23 M naloxone (P < 0.05), but increased significantly in the presence of 10 28 M (P < 0.001). Curvilinear velocity and amplitude of lateral head displacement in spermatozoa incubated in the presence of naloxone were not indicative of hyperactivation. H258/CTC staining showed that 10 28 M naloxone significantly stimulated capacitation (P < 0.01) after 3 h. However, it had no effect on sperm cell viability and acrosomal status. Overall, this study provides the first evidence that the m-opioid receptor is expressed in equine spermatozoa and that naloxone significantly affects motility and capacitation.