Chilled And Frozen Semen In Dogs 

Chilled Semen

Semen can be collected, processed and packaged in order to send to a breeder in another area of the UK or indeed Europe or North America.  Chilled semen can survive and fertilise eggs for around five days as long as it kept at the correct temperature.  Chilled semen transport boxes will keep semen at the correct temperature for 48 hours, so organising the collection and shipment to coincide with the ideal insemination time of the bitch is essential.

Chilled semen once inseminated doesn’t survive as long as fresh semen so frequent progesterone testing of the bitch is necessary a) to estimate the best time to collect the semen and b) to know exactly when to inseminate.

Millhouse can collect, centrifuge and add extender to your dog’s semen sample before packaging and shipping to its destination.  We have accounts with DHL and Fedex to facilitate this.  Of course the semen will be evaluated prior to cooling to ensure that the sample quality is good enough to use chilled.

Depending on the country of destination the stud dog may have to undergo some tests prior to sending the semen.  The high health status of dogs in the UK means this is uncommon but please check with APHA Carlisle and the destination country prior to the bitch coming into season.

To import chilled semen into the UK the stud must have a valid rabies vaccination.  An import licence from APHA is also necessary and maybe an export licence from the country of origin.  Millhouse can help you with the licensing procedures.

Transporting of chilled semen is much cheaper than transporting frozen semen, the downside of using chilled semen is having to coordinate the collection, the transport and the insemination (eg organising a courier over the Christmas period may be difficult). And since Brexit, entry requirements and the length of time it takes to courier semen to Europe has made chilled semen almost an impossibility.

Chilled semen can be inseminated into the cranial vagina or directly into the uterus (using an endoscope) if the quality of the semen is poor.

Frozen Semen

Canine semen can now be successfully frozen and used to inseminate bitches in almost any country in the world, and at any time in the future. Puppies have already been produced from semen which has been frozen for forty years.

Many breeds have very small gene pools and using a stud from another country may help to maintain good genetic health. Freezing your dog's semen while he is young and fit enables him to continue to produce puppies even if he later becomes infertile or suffers severe injury. It also enables you to use his genetic potential for future generations of puppies.

The freezing process and the transport of frozen semen is more expensive than the processing and transportation of chilled semen. However, it does allow for collection at a time which is convenient to you and it can then be transported well in advance of the date it is needed. It also means you can avoid the summer months when semen quality is generally poorer.
The freezing and thawing processes do affect the motility and subsequent longevity of the sperm, so only good quality semen samples should be stored. It also means that insemination directly into the uterus is a must.

At Millhouse, each semen sample will be evaluated prior to starting the freezing process, prostatic fluid will be removed and replaced with a cryoprotectant. The sample will be cooled and then frozen into 0.5ml straws which are stored in large flasks of liquid nitrogen at -196*C. The day after freezing a test straw will be thawed and the motility of the sperm cells will be checked. It is the number of live, motile sperm after thawing which determines how many straws are needed for future inseminations.

Indelible ink is used to label each straw with all the details of the stud dog and the date and place of collection. Different coloured straws, colour coded goblets and canes, and a robust recording system ensure we know which straw belongs to each stud dog.

Frozen straws are transported in a 'dry shipper' which has liquid nitrogen absorbed into it. This means it is safe to transport and the straws inside should remain frozen for up to 20 days. These 'dry shippers' are expensive to purchase and need to be returned to the clinic. They are also quite heavy and so transport costs are not insignificant, however, with prior knowledge it is possible to share costs with another owner exporting straws to the same destination. More recently, a shipper called a 'cryocube' has become available. It is lighter, but it only keeps the straws at -196*C for 5-7 days so may not be suitable for all exports. Both ' dry shippers' and cryocubes are available to hire or purchase from Millhouse.

Any straws frozen at Millhouse will remain the property of the owner of the stud dog at the time of collection unless we receive written authorisation to the contrary. We can store semen which has been collected here as well as semen from abroad awaiting insemination into a UK bitch.


Straws in liquid nitrogen for freezing and transporting semen