Recent advances in fertility preservation of dogs and cats

Strategies to preserve fertility in dogs and cats as cryopreservation of epididymal spermatozoa, oocytes and ovarian tissue will be discussed in this review . Recent results indicate that significant progress have been achieved, but optimal freezing protocols have not been defined yet. The extreme sensitivity of sperm membranes and of oocyte and ovarian tissue structur e deserves further investigations aimed at protecting male and female gametes from freezing injuries.