New Techniques in Artificial Insemination using Frozen Semen

By Laura Weber

Since the early 1980's, litters have been born using frozen semen. Breeders have collected, frozen and stored semen in hopes of passing exceptional genes on to future generations. This process entails a long lasting expense and, for Skye Terrier breeders, has not led to the happy results anticipated.

Breeders in our breed have tried many times to use their frozen semen and, to date, have met with no success that I have been able to find. (Please correct me if I am wrong!) Using the most up-to-date technology and the most experienced reproductive vets in the country, we, as a breed community, have not seen one puppy that I know of.

Now there may be a process in use in some advanced veterinary clinics and schools that may make this process more "productive" for our breed. If you have been waiting to use that precious frozen semen, read on.

The most used method for inseminating the thawed semen has been surgically. The bitch is sedated and an incision is made into the abdomen. The sperm is then inserted into the uterus using a needle and syringe. The reported pregnancy rate for this procedure is approx. 50%. Other techniques used can yield slightly higher results. 

However, the most promising of the new techniques is insemination using an endoscope. Dr. Margaret V. Root Kustritz, DVM, at the University of Minnesota Small Animal Clinic describes the procedure. 

"The endoscope is rigid and of a very narrow diameter, allowing it to be passed the entire length of the vagina. Other instruments cannot do this, due to the extreme length of the vagina in bitches and the presence of a fold of mucosa that hangs from the ceiling of the vagina just outside the cervix. The endoscope must be narrow enough to sneak beneath this fold, and rigid enough to ensure that it will not get caught in the folds of the vaginal mucosal lining. The endoscope is used to visualize the outer opening of the cervix and then a narrow polypropylene urinary catheter is passed through the cervix and into the uterus and the semen injected through that. Even a small volume of semen (1-2 ml) distends the entire uterine body and both uterine horns in most dogs, so the semen is going to get into the entire uterus no matter where you put it. 

"One study reported highest implantation rate with insemination 4 days after ovulation. Several studies have shown higher pregnancy rates with 2 inseminations. For two inseminations to be effected, all the semen can be sent in one liquid nitrogen canister, and then enough straws thawed at the time of each insemination for that insemination only. If the remaining straws are maintained in liquid nitrogen, they will be fine. The bitch need not be sedated if she is at the correct time of her cycle. The veterinarian that developed the technique, Dr. Marian Wilson of New Zealand, says that some very small dogs, some very long-bodied dogs, and some very nervous bitches cannot be inseminated with this technique."

"The pregnancy rate for natural service in the dog is generally considered to average 90%. While no form of artificial insemination equals or exceeds this value, insemination with endoscopy can produce as high as an 80% pregnancy rate.

My thanks to Dr. Root Kustritz for taking the time to educate me. We all hope that this new technique as well as others will help us accomplish what previous techniques have not, live puppies from frozen semen in Skye Terriers.