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Artificial Insemination - We know, do we?
asks Sierra Milton

A columnist in your contemporary made the following observations: "Why would anyone not want their dog to mate naturally but only by AI? This is the preferred method in America, we know, but what is the idea behind the custom? (author’s emphasis added) Is it a fear of damaging a precious show dog, maybe putting its back out, or maybe getting a nip from the bitch? Or might the dog lose weight through his exertions or become interested in the opposite sex?"

Those in the ‘we’ are sorely misinformed, since artificial insemination (AI) is NOT the preferred method of breeding in the USA. The statistics from the American Kennel Club clearly indicate that the vast majority of litters are naturally conceived. The AKC confirms that in 2003, there were 424,328 litters registered. Of these, the methods of conception for these litters were as follows:

423,712 litters naturally
341 litters using fresh semen artificial insemination
158 litters using frozen semen artificial insemination
117 litters using fresh extended semen artificial insemination

Clearly 99.9% of those breeding litters in the USA during 2003 ‘preferred’ natural matings.

What appears to be irresponsible journalism and lackadaisical research turns a figure of less than 0.1% into ‘preferred method’. Now that yet another piece of propaganda has been relegated to the bin where it belongs (along with all the other ills that have been attributed to United States purebred dogs), artificial insemination can be looked at dispassionately as the useful breeding tool it is.

As a comparison, sources at the KC stated that 40-50 applications approving artificial insemination requests are granted annually. There is currently, however, no means of determining which of these requests actually result in the procedure being carried out.

It is doubtful that anyone with even the remotest commonsense would believe that AI is used solely to prevent injury to a ‘precious show dog’ (the very term ‘precious’ disparaging those dogs that are shown). Dogs that cannot breed naturally should be eliminated from any sensible breeding program. The sole purpose of breeding is to improve the breed and to leave that breed in a far better condition than when the safekeeping of the breed was passed into the breeder’s hands. Ensuring that a bloodline of dogs, or even an entire breed, can only reproduce by artificial means certainly fails to fulfil that mandate.

Some breeders may be willing to pay expensive veterinarian costs in order to keep the stud dog from being nipped. This, however, is doubtful since those who are experienced in breeding will take other less costly means, such as a soft muzzle, to prevent the stud dog from being bitten.

Those who are very experienced will have also invested time in conditioning the stud dog so that their presence during breeding does not put a dampener on the proceedings. What some fail to consider is that collection of the semen most often is done with a ‘teaser’ bitch and, though one would hope the bitch would be amorous, there is no guarantees that a nip or two might not ensue. Some stud dogs get more excited by the bitch being a bit standoffish and that ‘nip’ might actually be part of foreplay.

Might the dog lose weight through his exertions? If so, the dog will still lose weight since he is still going to have to undergo the same process, whether into a beaker or a bitch. Few dogs that are not interested in the opposite sex will cooperate with the breeding process, artificial or not, so assuredly, the opposite sex must have some attraction.

Rather than sneer at AI in general, and insult the American breeding practices in particular, it would prove far more beneficial to look at the reasons when artificial insemination should be seriously considered and how such considerations can improve dogs here in the UK.

Vast distances

The United Kingdom covers an area roughly equal to the state of Oregon in the US. When considering the vast distances in the US, artificial insemination has made it possible to breed a bitch from the East Coast to a dog over three thousand miles away on the West Coast without the dangers of flying the bitch to the dog, eliminating a great deal of risk, cost and time. Unless the owner travels with the bitch, expending yet more money, the bitch would be met at the airport by strangers, kept in a locale strange to her, handled during the mating by those she has just met, and then placed back on the plane and shipped back home some days later.

Instead, the owner can safely breed the bitch at the optimum time to the best possible dog with the minimum of disruption. Using a top quality dog is now feasible instead of using a dog that is nearer, but more accessible, and possibly of lesser quality. It would even be possible with the global air travel to use fresh chilled semen instead of frozen, although the window is shorter (maximum viability is 48 hours, though the semen may be used up for up to six days after chilling).

In the United States, there are over 1500 championship shows held each year as opposed to the thirty or so here in the UK, dependent upon the breed. Those dogs vying for top rankings in their breed, group, and all-breeds will be shown at well over 120 championship events a year. Frozen semen collection means that these dogs are still available for breeding without a major travel campaign to determine where the bitch can meet the dog off show grounds (breeding on show grounds is not permissible under AKC rules). This is seldom a problem here in the UK where most often the dogs being bred are normally at the same shows. Until one has actually campaigned a top show dog in the US, or even a heavily campaigned dog, it is difficult to understand the logistics that need to be considered.

Another possible reason for using artificial insemination, particularly fresh semen, is if the dog has been temporarily or permanently injured. While the injury may prevent the dog from tying with a bitch, unless the disability is genetic or structural unsoundness, such an injury should not remove a high quality animal from a valuable gene pool. Bitches with strictures, unable to breed naturally, can be inseminated through surgical or laparoscopic insemination and still produce a healthy litter.

Those who utilise artificial insemination should as a normal course ensure that the quality of the semen is evaluated. Ideally, the semen would be evaluated prior to the actual day of mating for those dogs that are used more than infrequently. Semen is normally evaluated prior to being frozen. In the case of fresh or fresh chilled, the semen can be diagnostically evaluated prior to inseminating the bitch. Such evaluations give a valuable insight and can lead to quick therapeutic measures, sometimes before the infertility is irreversible. Even frequently ‘naturally bred’ dogs can become sub-fertile or even sterile. Knowing in advance that the semen is viable often saves the bitch’s owner great disappointment and money.

When should artificial insemination not be used?

l When temperament problems make it impossible to naturally breed the dogs.

l When there are physical problems, other than injury, that would make natural breeding impossible.

l When it perpetuates the inability of a breed to naturally conceive litters.

l When the injury or ailment is one that is rampant or pervasive in the breed.

One of the greatest threats facing many breeds here in the UK is an ever-increasing smaller gene pool. A large portion of the diminished gene pool can be attributed to the ‘popular sire syndrome’ whereby those dogs that are winning events are used. The over-utilisation of popular sires and the underutilisation of others lead to loss of genetic diversity, the fixing of genetic frequency, and subjecting the resultant pool to genetic drift. As Dr. Jerold S. Bell, DVM, points out: "Regardless of the popularity of the breed, if everyone is breeding to a single stud, (the popular sire syndrome) the gene pool will drift in that individual’s direction and there will be a loss of genetic diversity. The frequency of his genes will increase, possibly fixing breed related genetic disease through the founder’s effect."

Another factor creating the shrinkage of the gene pool can be found in the isolationism previously forced upon UK breeders through quarantine laws which made it difficult to travel or ship a bitch for breeding. This restriction has been removed with the recent introduction of the pet passport scheme, although many breeders still blindly cling to the isolationist doctrine. Though DEFRA regulations regarding the importation of frozen semen may be onerous, artificial insemination does allow for genetic pools to be diversified and refreshed through the use of quality dogs from other countries.

While semen can be frozen and used generations later, care must be taken that the use of this semen does not perpetuate the smaller gene pool problem. One solution used by a breeder in the US was to freeze a very limited amount of semen from her top-producing, Hall of Fame dog. Because only a small amount was
frozen, she was very careful in screening which bitches would be considered for artificial insemination by that dog. One of the dangers of freezing popular sires’ semen is, of course, that the popular sire syndrome can go on for years after the natural demise of the stud dog.

The use of artificial insemination using either chilled or frozen semen reduces risks and stress of shipping. Some bitches may "go out of season" suddenly after shipping, causing a failure to ovulate which can be a result of stress-induced changes in hormone secretions. Airline travel may be precarious particularly in extreme temperatures and may even be prohibited, further restricting the choice of studs. Further, both dogs and bitches will frequently become stressed in strange environments, causing decreased reproductive efficiencies.

Some stud dog owners limit or prohibit the use of a dog for breeding because they prefer to not take the arduous responsibility for caring for the bitch during breeding or managing the breeding act itself. Caring for someone else’s valuable bitch, particularly one that is easily stressed by increased hormonal activity and a strange environment, is not a task that many stud owners wish to undertake. Others prefer to not disrupt their kennel by introducing an ovulating bitch into their environment. For those bitches that are shipped, some potential stud dog owners do not have the time or ability to arrange to pick the bitch up and deliver her again after the breeding to the airport. The use of frozen or chilled semen and artificial insemination allows for dogs that otherwise would be barred to be used in the gene pool.
Clearly, the use of artificial insemination also reduces the risk of sexually transmitted diseases.

Artificial insemination is certainly not done to save money. Estimated costs for initial collection and freezing of semen is around £400 and yearly maintenance of the collected semen is about £50. The cost for artificially inseminating the bitch is also not inexpensive.

Surgical implantation, done by laparoscopy, is normally the recommended procedure for optimum results when using frozen semen. Because the success rate is influenced by the experience of the veterinarian thawing and inseminating the semen, lower litter sizes can result. The quality of the semen, the timing of insemination and using the correct number of high-quality sperm cells produce the largest litters of healthy puppies. The UK is further hampered by the lack of trained veterinarians willing and able to do artificial insemination with chilled or frozen sperm.

Insemination is done by one of four different methods:

l Vaginal insemination – While the bitch is in a standing position with her rear elevated, a catheter loaded with semen is inserted into the vagina and advanced to the cervix opening.

Once the catheter is in place, the semen is ‘pumped’ into the uterus and the catheter withdrawn. Ideally, the inseminator should digitally stroke (‘feather’) the roof of the vaginal tract for one to two minutes after insemination to simulate a natural breeding tie. The bitch’s rear is kept elevated for two to three minutes after insemination. Sedation is rarely required. This technique most closely mimics the act of natural mating.

l Transcervical insemination – A fibre optic cystourethoscope is used vaginally to see the opening to the cervix. A flexible catheter is inserted through the cervix into the uterus.

While transcervical insemination (TCI) does not allow for the uterus to be evaluated, the process does enable the vaginal tract to be examined through visualisation on a television monitor. Once the catheter is inserted into the uterus, the semen is gently pushed through the catheter from a syringe. The use of the cystourethoscope makes it possible for the inseminator to see that the semen flows easily into the vagina and does not flow back into the vaginal tract. This technique is recommended for any type of semen, particularly frozen and fresh-cooled. A significant increase in conception rates can be obtained over natural breeding methods when poor quality semen and/or lowered sperm numbers are being used. TCI should be considered for use on bitches less than five years of age when there is no reason to suspect uterine changes or disease.

l Surgical insemination – An invasive procedure similar to the technique used to spay a bitch, the semen is injected directly into the exposed uterus through a small hypodermic needle.

The uterus proper is not incised. The veterinarian is able to carefully examine the uterine wall thickness and muscle texture, as well as endometrial cysts which may not only interfere with the ability of the semen to reach the fallopian tubes, but may also prevent implantation of the fertilised ova and inhibit placental development and growth. While allowing for examination of bitches suspected of having uterine or ovarian diseases, surgical insemination also most closely matches the conception rates of natural breedings. Some giant and toy breeds, particularly those with historically poor conception rates can benefit from the surgical technique as will males with low sperm-cell counts that would otherwise have difficulty impregnating bitches in natural matings.

Surgical insemination is particularly useful on bitches over five years of age. One of the concerns, though, would be that the low sperm count is not genetically caused; the benefit of using a low sperm-count male, regardless of his overall quality, would have to be carefully weighed by the breeder. Whether it is ethically acceptable to achieve pregnancies by resorting to surgery is debatable. While costly and time-consuming, this method is also obviously very stressful to the bitch and has risks of infection, sedation sensitivity and other factors associated with surgery in general.

l Laparoscopic insemination – Less invasive and potentially faster than the surgical technique, laparoscopic insemination is performed by inserting a small telescope through a small incision in the abdominal wall to locate and identify the uterus. The semen is then injected directly into the uterus through syringe with a small hypodermic needle. Similar in advantages and conception rates to surgical insemination, the laparoscopic technique does not allow for manual examination of the uterus, but does enable the veterinarian to see the uterus.

One of the factors that must be considered when deciding which technique will be used is that the ova ovulated by a bitch is not immediately ready for fertilisation. The ova must first mature. The final melotic division stage does not occur for a minimum of 48 hours post ovulation. After thawing and insemination, frozen semen is believed to live for only 12-24 hours in the uterus. Because frozen semen has such a short life, vaginal insemination has proved minimally effective and optimum results are obtained with direct uterine implantation.

Other factors also influence the breeder’s ability to utilise artificial insemination as a tool in their breeding programme. Within the UK there are only a handful of veterinarians able to perform artificial insemination procedures. Theoretical techniques are covered as a part of the educational courses undertaken by veterinarians. Unfortunately practical or ‘hands-on’ experience is not afforded during the courses. Reproductive specialities, similar to the specialities of ophthalmology, orthopaedics and the like, also involve additional training.

Those veterinarians desiring reproductive specialisation most often travel to Europe or the United States to complete their studies. The scarcity of such specialists here in the UK affects the distances the breeder must travel, the costs involved, as well as the conception success rates.

Success rates with artificial insemination are climbing in both the US and Canada because of advances in semen collection, extending and storage, and in improved insemination techniques. The KC still requires individual approval of applications for litters using artificial insemination techniques, regardless of whether frozen, fresh chilled or frozen sperm is used or vaginal, TCI, laparoscopic or surgical methods are utilised. The US and Canada no longer requires such individual approval. The American Kennel Club requires DNA certification for all stud dogs whose semen is collected for fresh chilled or frozen use. DNA certification is not necessary in the US for those matings where both the dog and bitch are present.

Natural breedings are still the best and most successful method of producing puppies. However, artificial insemination is a very valuable tool and should never be scoffed at as being either ‘improper’ or as a ‘fad.’ Do not be afraid to use frozen semen to improve your breeding programme if you believe that the dog on the other side of the country or world is the best for your plans and for your bitch. Let the gossips find something else to sneer at and you be part of the brave new world that dares to search out solutions instead of problems.

© 2004 Sierra Milton sierra.milton@ntlworld.com

 

Sierra Milton is a monthly feature writer for the Canine Chronicle, one of the largest show dog publications in the United States, and has been featured in various breed publications throughout the world. She has been involved in dogs for over 36 years and has shown dogs throughout the US and Canada. Having owned and bred German Shorthaired Pointers for the past 27 years, along with her husband she shows under the Stormsong affix in Europe.