The most important aspect when discussing artificial insemination (AI) is to realize that there are many factors that play a role in whether or not your
bitch becomes pregnant after AI. These factors include; type of semen (fresh vs frozen), semen quality and quantity, age and fertility of both the
stud dog and bitch, site of semen deposition (intrauterine vs vaginal) and time of insemination…. just to name a few! As you can see, it is very
important that when comparing “conception” or more correctly, “pregnancy rates” that all of these factors should be considered. Usually a combination
of these factors are acting together in any one case.
1: Types of Semen: Fresh, Chilled and Frozen
Insemination can be performed using three types of canine semen: fresh, fresh-chilled and frozen.
a) Fresh ejaculated canine semen has the longest viability. Semen from young, fertile stud dogs can survive for up to 3 to 3 days in the bitch’s
b) Fresh-Chilled semen
This involves the dilution of ejaculated semen in special canine extenders which contain egg yolk and buffers that protect the sperm during the cooling process. The extended semen is then slowly cooled to 4°C and can remain viable at 4°C for up to 2-3 days. Semen from some stud dogs has been reported to maintain viability and fertility after storage at 4°C for much longer, but it prefers body temperature! Once the semen is collected from the stud dog it is evaluated and then extended to an appropriate concentration and volume in special “canine semen chilling extender”. The extended semen is then placed in a special transport box that cools the semen to 4°C while it is in transit to the bitch’s location. Once the semen reaches 4°C it is then held at this temperature for about 24 hrs depending
on the transport system used and the outside temperature. The objective of chilling semen is to conserve the sperm's energy and hence prolong its longevity and viability. After warming back up to body temperature, fresh chilled semen lives about 24 to 72 hours in the bitch although with some stud dogs the sperm last a lot longer.