Xylazine does not Induce Retrograde Flow of Spermatozoa into the Urinary Bladder of Sexually Rested Boars

Abstract

The effect of xylazine on the retrograde flow of spermatozoa from their storage sites in the epididymides and vasa deferentia into the urinary bladder of sexually rested boars was examined. The bladder of four boars was evacuated through a surgically implanted urinary catheter and the urine was examined for the presence of spermatozoa. Boars were then given an injection of 2.2 mg of xylazine per kilogram of body weight and, immediately thereafter, 500 ml of saline was infused into the urinary bladder. Approximately 50 ml of the post-treatment mixture of urine and saline, referred to as 'urine', was collected through the catheter at 5, 10, 15, 20, 30 and 45 min after the injection of xylazine, and examined immediately for the presence and motility of spermatozoa. At 60 min, the urinary bladder was evacuated and the remaining 'urine' was examined for the presence and motility of spermatozoa. None of the pre-xylazine urine and post-xylazine fractions of 'urine' had motile spermatozoa and xylazine did not increase (P > 0.1) the concentration and the number of spermatozoa in the post-treatment 'urine'. Thus, in contrast to other species, xylazine does not induce retrograde flow of spermatozoa into the urinary bladder of boars.

Effects of atipamezole and medetomidine administration on seminal variables and functions of erection and ejaculation of the collared peccary (Tayassu tajacu) after electroejaculation

“…Sperm were found in all dog urine samples after ejaculation, despite the fact that the pretreatment with sympathomimetic agents significantly decreased the retrograde flow [ 31 ]. In contrast, no significant differences in the percentage of the retrograde flow of sperm were observed after the administration of xylazine in pigs [ 32 ] or medetomidine in cats [ 22 ]. The same authors also assert that a small amount of sperm can be found in the urine of cats after electroejaculation even without the use of a chemical restraint or an ejaculation stimulus.…”

Combinación de ketamina y xilacina para reducir el dolor durante la electroeyaculación en perros

“…Another common problem observed during EEJ procedures is urine-contaminated semen. In order to avoid this, α-2 adrenergic action of xylazine combined with ketamine is used to induce bladder neck closure (Martin et al, 2003).…”