Survival of several species, along with preservation of the genetic pool is only viable if we can guarantee its conservation throughout time. Canine semen cryopreservation consists on chilling and freezing techniques. Dog semen possesses certain resilience to chilling procedures, which cannot assure long-term gamete preservation. Freezing methods induce a decrease of quality. To overcome this, several extenders to protect spermatozoa have been studied and methods were developed to evaluate both quality and induced damage to the sperm cell by cryopreservation. Yet, it is still difficult to...