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Artificial insemination has been done for many years, but the ability to freeze semen and chill and ship semen has dramatically changed the ability to do planned breedings with incredible success. Vaginal, transcervical, and surgical inseminations are now the norm for many kennels, and it is now possible to successfully breed with semen from almost anywhere in the world reducing stress for the bitch and travel costs for the breeder.
Dr. William Schultz, a well-recognized expert in canine reproduction and member of The Society for Theriogenology, shares tips for success with fresh, chilled semen breedings.
Environment Of The Collection Area
In our clinic, we collect in the same exam room so that the stud will become familiar with this room. We do not vaccinate or do other procedures with studs in this room. The stud is brought in the room and allowed time to acclimate and sniff around. Large breeds are collected on the floor and smaller breeds are collected on the examination table.
In a kennel, the collection area should be isolated as much as possible – sometimes a quiet store room area can be used. Keeping the outside distractions to a minimum is always helpful.
We use a disposable artificial vagina for the collection. These are cone shaped with the end cut off to allow the placement of a 15-milliliter centrifuge tube. The tubes may be changed during the collection to separate the semen fractions. The wide end of the cone may be folded to the outside to adjust the length to accommodate different size stud dogs.
A teaser bitch is extremely important and in some males she may need to be in full standing heat. We have had inexperienced males not release sperm rich fraction without a standing teaser. This may lead to an incorrect diagnosis of infertility.
Avoid wearing white coats, and act relaxed, friendly, and non-threatening. The collection may be performed on the floor or on a table, depending on what the stud is used to. If there is a particular item that the stud associates with breeding, such as a rug or breeding rack, have the owner bring it along.
All equipment must be at room temperature. Use disposable artificial vaginas attached to 15-milliliter centrifuge tubes with docking rings. Fold the large end of the artificial vagina inside out, about 1 inch for large dogs (larger than 40 pounds) and 3-4 inches for small dogs (smaller than 40 pounds). The use of a lubricant is not recommended, as it is rarely necessary and many are spermicidal. Have three to five additional disposable artificial vaginas at hand.
To provide adequate footing for the stud, place a rubber-backed mat or a piece of carpet on the floor or table.
Using A Teaser Bitch
In almost all cases, the teaser will significantly increase the ease of collection and the volume of the collection. It is the single sperm that completes the insemination but it takes millions to billions of sperm to get to that point.
If no teaser is available, use swabs that were used for vaginal cytology in previous bitches. We keep the swabs in a baggie in the refrigerator and allow the male to sniff the swabs. If a bitch is used that is not in heat, the swabs may be rubbed near her anal and vulvar area simulating a bitch in heat. It is important to closely control the non-cycling bitch because she may become very aggressive if male tries to mounts her.
If at all possible, have an estrus teaser bitch available that is approximately the same size as the stud dog. A handler or technician should be available to support the bitch in a standing position and restrain her if necessary. If that is not possible, use an anestrous bitch, restrained in standing position. It may be useful to keep some swabs of estrus vaginal secretions frozen. Thaw these by dipping them in warm water, and then wipe them on the vulva of a teaser not in season.
Often, 30 to 50 percent more sperm cells will be released when a suitable teaser is used. Many dogs may have semen collected without a teaser bitch, but semen quality is generally better when an estrus teaser bitch is present and the stud’s libido is highest. An alternate training tool is a pheromone such as Eau d’ Estrus.
The male is allowed to acclimate and to interact with the teaser before any attempt is made at collecting. The least number of owners and assistants in the room is also necessary to decrease the level of distraction. However, a good stud dog will not be bothered as long as a teaser is present.
When performing semen collections, take care to make the stud dog feel as comfortable as possible.
Properly Collecting Semen
Taking the male for a walk and allowing him to urinate before the collection is helpful. This should be done completely away from the teaser if possible.
With the bitch in position, bring the stud into the room. Allow him to familiarize himself with his surroundings, with the bitch, and with you.
If the teaser is not to be bred, be careful at this time that he does not rapidly mount and tie the bitch.
I sit in a low chair to allow rapid movement while the stud is allowed to mount the bitch. Being just to the side of the stud will allow for movement of the stud and still remain close enough to use the artificial vagina for the collection. It is important to have enough room to allow the stud to mount and then dismount during the collection.
Allow the male to mount. As he begins to thrust, gently massage the preputial sheath with one hand. If the male shows little interest in the bitch and does not mount, you may massage the sheath to stimulate an erection.
As erection occurs, pull the sheath behind the bulbus glandis. At the same time, with the other hand, slip the artificial vagina over the penis to just below the bulbus glandis.
Be careful when reflecting the sheath that the male does not have the bulbus glandis engorged. It is very painful, if not impossible, to reflect the sheath after the bulbus glandis has engorged. If needed the male may be removed from the room and walked until the bulbus glandis has gone down and then attempt the collection again. In some very aggressive studs, it may be necessary to collect the sample with the sheath partially covering the bulbus glandis.
Reposition your hands providing gentle but constant pressure just proximal to and incorporating the bulbus glandis. You may stimulate the penis caudal to the bulbus glandis with your other hand.
Most dogs will thrust initially, coinciding with the penetration. They achieve full erection coinciding with the “tie,” and will try to step over the bitch and your arm. You may help the stud by lifting his leg over your arm and turning his penis 180 degrees, so it is directed backwards between his legs.
You should be able to visualize the semen as it flows into the clear tube. Most dogs ejaculate in three fractions: an initial clear or slightly cloudy pre-ejaculate fraction, the sperm-rich fraction (SRF), and a clear fraction of prostatic fluid. The initial clear fraction is released during the period of vigorous thrusting. The SRF should appear as a thick, white, creamy liquid, which is usually released just as vigorous thrusting stops and the stud steps over. In some studs the SRF maybe thin white and the volume may vary from ½ to 10 cubic centimeters. The clear prostatic fluid follows in varying amounts. When the SRF has been released and the first prostatic fluid is noted the collection is stopped.
Switch tubes attached to the artificial vagina during the collection to separate the fractions. If no centrifuge is available it is important to separate the fractions. After microscopic evaluation, the contents of tubes changed too early may be combined, if appropriate. Make sure you have collected the entire SRF before stopping. It is not necessary to collect the entire third fraction; save just enough to evaluate for abnormal cells, bacteria, etc.
It is very important to make sure the erection has subsided after the collection. In the winter frostbite is possible, and the male should never be allowed outside on cold days when the erection is present. Walking the stud after the collection will decrease the time needed to lose the erection. If the penis appears dry, you may apply a sterile lubricant at this stage. Make sure the penis is fully retracted into the sheath before putting the dog into a cage or with other dogs.
Storing And Chilling Semen
If the fresh semen is not to be used for several days it may be centrifuged with Semen Separating Solution and extended with Fresh Express Extender. The extended semen is labeled and put in a beaker with water and placed in a 40-degree Fahrenheit refrigerator. The purpose of the water bath is to keep the sample from rapid warming and chilling if the refrigerator is opened. Our refrigerator is at a constant 40 degrees while most refrigerators turn on and off with a 5-to-8-degree temperature variation. Using this method, we have successfully stored semen over three weeks for a breeding. The semen is checked every two to three days and the extender is changed as necessary to keep motility at the best level possible.
When Should Insemination Be Performed?
Once the LH surge has been identified in the bitch, count forward to determine the fertile period. The day of the LH surge is designated as day zero. Days 4-7 after the LH surge encompass the true fertile period, with peak fertility on days 5 and 6. We do vaginal or transcervical breedings on days 3 and 5 after the progesterone rise or LH surge, with frozen semen breedings on day 5.
Breedings dates may vary with the reproduction vet being used for the breeding. The probability of successful fertilization is optimized by properly planning inseminations.
Dr. Schultz is a well-recognized expert in canine reproduction. He received his DVM from Michigan State University in 1973, went into private practice and opened his companion animal practice in the fall of 1974. He is a member of The Society for Theriogenology and The Theriogenology Foundation, and is a frequent speaker at veterinary conferences, veterinary associations and national specialties.
This is an advertorial sponsored by Zoetis.
The following information was originally released by the AKC Canine Health Foundation as a podcast. If you prefer to listen to the interview, the podcast is available here.