submitted with permission by Marj Brooks
The canid is generally fertile with about 80% successful matings ending in pregnancy by natural methods. With clinical procedures success rate is approximately 70 – 80%. The best method is to mate the dogs naturally wherever possible but clinical intervention is a useful adjunct to a successful breeding program. Obviously the more intervention and skill required by the veterinary staff that is required, is the more expensive it will be. Below is presented a table for comparison of mating methods.
Currently there are four approaches that can be taken to attempt to impregnate the bitch:
- natural mating
- artificial insemination
- surgical insemination
- transcervical insemination
Embryonic transplantation is being researched and may be available as soon as four years.
To improve chances of impregnation and a healthy litter the owner can:
- request cytology smears to establish stage of oestrus (not very accurate)
- commence Progesterone testing at the start of oestrus to establish time of ovulation
- swab the bitch for evidence of pathogenic bacteria and treat if necessary
All dogs generally requires some human assistance to reduce the risk of injuring themselves during mating as they are large dogs and back injuries are possible. A mating rack/bitch hitch can be used if the male will tolerate its presence. The male as well as the female should be swabbed prior to mating to ensure minimal risk of transference of bacteria during the mating process. It does absolutely no harm to the dog or bitch to mate them every two days from ovulation until one or the other refuses. Semen evaluation approximately one week prior to mating is money well spent as it can give the owner of the bitch time to organise another male if the semen quality is poor or to seek veterinary advice for the best way to maximise chances of pregnancy with a sub-fertile male.
This method is useful when there is a physical or psychological problem that prevents the dog or bitch mating but natural mating should always be the first option where possible. This requires that the bitch be progesterone tested to pinpoint time of ovulation for maximising success rates. This procedure involves collecting the semen of the male and inserting it into a bitch via a syringe and lumen. Veterinary equipment has improved to the point that lumens with inflatable bulbs to simulate a tie are now being used. Failing that, the vaginal canal should be feathered and the bitch should be allowed to stand with her rear end elevated for at least 15 minutes post insertion This method can increase the risk of infection if the equipment is not clean. This method requires a semen work up to make sure that the dog is fertile prior to insemination. Three inseminations, two days apart are usually recommended. With this method long distance matings are achieved as fresh chilled semen can be flown interstate once it has been mixed with an extender and is viable for a few days.
This method is the most invasive as it involves a surgical incision to insert the semen directly into the uterine horn in the anaesthetised bitch. This procedure is conducted once. Again a progesterone workup is a must to pinpoint the LH surge to be able to predict within 12 hours of accuracy, ovulation time. The ova then require another 48 hours to mature or ripen. This method is usually used for frozen semen as its viability, motility and concentration is reduced. This method is also recommended when the male is considered to be clinically infertile i.e: low sperm count. Also this method can be used if the reproductive tract has been demonstrated to be hostile to sperm due to pH fluctuations. Success rate is approx 70 – 80% and allows for matings that would be otherwise impossible due to geographical distances involved or if the male has died or is no longer fertile. Frozen semen can be stored in liquid nitrogen for an undetermined amount of time without any deleterious effects noted on the semen quality. Five straws of semen are usually required. One for post thaw studies and four for implantation.
This procedure is still in its early stages. This involves implantation of the raw semen directly into the uterus using a flexible cytoscope through the cervix. Work is also being conducted as to its efficacy rates with frozen semen. The bitch does not require anaesthesia with this method. Progesterone work up is recommended to maximise chances of conception. The bitch needs to be restrained as the procedure is uncomfortable and the bitch needs to be kept very still during the procedure.
COMPARISON OF MATING TECHNIQUES
|ITEM||NATURAL||FRESH AI||SURGICAL AI||TRANSCERVICAL AI|
|health risks to dam||minimal||mild||increased||mild|
|frequency||2nd daily||2nd daily||once||once / ?twice|
|semen type||n / a||fresh||frozen / fresh||fresh / ? frozen|
|insemination cost||stud fee only||approx $75 ea||approx $500.00||approx $100.00ea|
Choice of Method Can Depend on:
- importance of mating
- availability and location of the sire
- type of semen available
- fertility of the sire
- mating ability of the dogs
- compliance of the dogs
- consideration of risks and benefits
- restriction of costs
- personal preferences