Artificial insemination in dogs

Artificial insemination (AI) in dogs is used primarily when natural breeding cannot be accomplished. Transporting semen, rather than live animals, to distant geographic locations is a great advantage of AI over natural service. AI is also used when behavioral problems, such as partner preference, or physical problems, such as vaginal prolapse, prevent copulation of the desired pair of dogs.

Some dog breeders prefer AI because they believe that the risks of breeding trauma is minimized and that the stud is less likely to be exposed to infectious diseases carried by the bitch. In addition, a single ejaculate with sufficient numbers of spermatozoa can be divided and used to inseminate several bitches. Although the number of viable spermatozoa necessary to maintain conception rates and litter size has not been determined for dogs, 150 to 200 X 10 000 000 viable spermatozoa is considered the minimum desirable number for intravaginal insemination. However, pregnancies produced by intrauterine insemination have been achieved under ideal conditions with as few as 20 X 10 000 000 fresh spermatozoa.

Several factors determine the success of artificial insemination in dogs, including the reproductive health of the animals, the quality of the semen, the timing and the number of inseminations, and the technical skills of the person performing the insemination. First and foremost is the reproductive health of the male and female. Normal dogs are expected to be willing and able to breed. However, various causes of reluctance to breed may make dog artificial insemination necessary. On the other hand, the problem that necessitated AI may also adversely affect fertility.

Second, the timing of insemination in dogs is critical. Animals may be brought in for AI because the usual behavioral signs of estrus are not manifested or recognized. In such cases, estrus may be identified by exfoliative vaginal cytology and ovulation can be estimated by serum luteinizing hormone (LH) or progesterone concentrations. Ideally, several inseminations are planned for a particular estrous cycle, because it has been shown that conception rates and litter size are better if bitches are bred two or three times than if the are bred once. If only two inseminations are included in the stud fee, which is common practice, the second insemination would ideally occur 48 or more hours after the first insemination during the fertile period.

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