A case trial study of the effect of ageing on fresh and post-thaw sperm in dogs.

The aim of this study was to compare fresh and post-thaw sperm morphofunctionality of young and old dogs of a case trial study. Young dogs had higher libido and fresh semen motility, vigour and plasmatic membrane integrity. Conversely, senile dogs had higher percentage of major sperm defects (proximal droplets). Young dogs presented higher post-thaw sperm acrosomal membrane integrity and lower percentage of sperm defects compared to senile dogs. In conclusion, senility has deleterious effect on fresh semen, causing high incidence of defected spermatozoa and plasma membrane lesion, decreasing sperm motility and vigour. Moreover, senile dogs are more susceptible to sperm cryodamage.