Spermatozoa Set New Speed Record

Customs originate because they once served a need. Unfortunately, we may continue to honor tradition because we don’t know there is a better way.

The patience (and backs) of a lot of breeders have been strained in efforts to insure conception through the practice of elevating a bitch’s hindquarters. We have long been advised to hold her up at least ten minutes and most breeders believe twenty minutes is even better insurance. Many experts also employ other insider tips such as simulating the tie and stimulating the bitch. The process is frightening for many toy dogs and backbreaking work for those with large breeds.

Spermatozoa Set New Speed RecordSo how long does it take for sperm cells to migrate through the female reproductive tract? Would you believe that spermatozoa from fresh ejaculates reach the tip of the uterine horn within 25 to 120 seconds after intravaginal insemination? It’s true, according to an article published in the Japanese Journal of Veterinary Science 1989;51:560-565. So, based on this information, is elevating the bitch’s hindquarters for extended periods of time really necessary?

Based on the results of a research study performed by C.R.F. Pinto, B.E. Eilts, and D.L. Paccamonti, (Theriogenology 1998;50:301-305), the practice of elevating the bitch’s hindquarters for more than one minute may be totally unnecessary! The study compared the success rates of two different hindquarter elevation times: 10 minutes versus 1 minute. The trial used 3 dogs and 15 bitches of proven fertility. Inseminations were performed intravaginally with fresh undiluted semen. The study was performed at Louisiana State University School of Veterinary Medicine and reports an overall pregnancy rate of 91% with litters averaging over seven puppies in both study groups. Statistically there was no difference in pregnancy rate or litter size in this comparison of 10 minute versus 1 minute hindquarter elevation time.

Also noteworthy for breeders is that “feathering or stroking of the vulvar and perineal region was not performed in any of the bitches” nor was there any attempt to simulate a tie by use of inflated balloons or other means. The bitches were immediately returned to their runs with no attempt to prevent sitting or urination.

In summary, the results of this study indicate that pregnancy rate in dogs with normal fertility is unaffected by reducing the hindquarter elevation time from 10 to 1 min following artificial insemination with fresh semen. Likewise, litter size is not affected by reducing hindquarter elevation time after insemination.

Well, so much for tradition. The practices of elevating hindquarters for uncomfortable stretches of time, genital area stimulation, and crating the bitch to prevent sitting or urination are relegated to the status of “old wives tales” thanks to this study.

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