Collection of epididymal semen in the tomcat (Felix catus) by stereomicroscope-aided retrograde flushing (SARF) improves sample quality

In small and laboratory animals epididymal spermatozoa can be collected only by the mincing technique however, blood and cell debris contamination may adversely affect the quality of the samples. This study aimed at performing the retrograde flushing technique, for the first time, in the tomcat. In the first experiment attempts to insert a blunted needle into tomcats’ ductus deferentes were made and the cannulation time and the success rate were recorded. In the second experiment, insertion of the needle into the ductus was carried out under a stereomicroscope for one testis, while the other was submitted to mincing for sperm recovery and the samples obtained from paired testes were compared. In the first study, only twenty-eight percent of the cannulation attempts were successful whereas in the second experiment, 91% of the deferentes were successfully cannulated: 80% of the ducts were cannulated in less than three minutes. The stereomicroscope-aided retrograde flushing samples showed significantly higher sperm viability, motility and velocities, as compared to those resulted from mincing. The domestic cat serves as a model for more than 36 species of wild felids; the developed stereomicroscope-aided retrograde flushing technique has the potential to become the gold standard method for harvesting spermatozoa of endangered species that have a small ductus deferens. •The tomcat ductus deferens could be cannulated under the stereomicroscope.•The cannulation could be performed in a short time with the stereomicroscope.•Compared to mincing, the retrograde flushing improved the sperm parameters.•The RF could be the gold standard for epididimal sperm collection in small animals.