Ejaculation Effect on Canine Prostatic Specific Esterase Serum Concentration

SIMPLE SUMMARY: Canine andrology has become an important area within veterinary practice. In this field, the prostate plays a crucial role; it can be affected by several illnesses, strongly influencing male fertility. The diagnosis of such diseases relies on different procedures; among them, following the example of human medicine, the study of serum biomarkers has led to the use of Canine Prostatic Specific Esterase (CPSE) as a first-line tool. The CPSE is influenced neither by circadian rhythms nor by transrectal palpation. The present study aimed to evaluate the effect of ejaculation on CPSE, both in healthy animals and in subjects with prostatic disorders. Soon after ejaculation, CPSE concentrations in serum are significantly higher than basal ones; they then return to their original concentrations in 24 h. At all times, CPSE is higher in affected dogs than in normal subjects; however, some healthy patients could be misdiagnosed with prostatic disorders based on the CPSE concentrations measured soon after ejaculation. Thus, in accordance with recent reports on canine prostate ultrasonography, a sexual rest of minimum 24 h should be applied before a thorough examination of the male genital tract. ABSTRACT: Canine prostatic diseases are usually asymptomatic in their onset and often identified in advanced stages. Canine prostatic specific esterase (CPSE) represents an early serum marker for prostatic diseases, also in asymptomatic dogs. The present study aimed to identify the effects of ejaculation on serum CPSE. Twenty adult intact male dogs were enrolled. Blood samples were collected to measure CPSE concentrations before (T0), immediately after (T1), and 24 h post (T2) ejaculation. Data were compared within and between groups by ANOVA (p < 0.05). Dogs were divided in two equal groups: A (healthy: CPSE ≤ 52.3 ng/mL at T0) and B (suspected for prostatic disorders: CPSE > 52.3 ng/mL or diagnosed with symptoms of prostatic diseases: CPSE > 90 ng/mL). CPSE was shown to be statistically higher in group B than A at any time point. In both groups, CPSE showed a significant increase at T1, and no significant differences between T0 and T2. This study demonstrates a definite effect of ejaculation on CPSE concentration. Twenty-four hours post-ejaculation, CPSE returns to basal values. Such physiological effects of ejaculation should be considered when planning analyses of CPSE concentrations, i.e., by respecting a proper sexual rest.