One of the questions I am frequently asked by fellow Rottweiler friends is how can I increase the odds of my bitches getting pregnant. In turn I have read many medical journals on the subject of estrus prediction in canines and would like to present the following ideas based on these articles and the numerous successful breedings we have had with our dogs and those sent to us for breeding.

The simple goal in any breeding program is to have sufficient sperm numbers present in the uterus in order to achieve fertilization of the eggs present. Numerous studies have shown that eggs are typically fertilized 3 to 8 days following the LH, Leutinizing Hormone, surge. This corresponds roughly to a period beginning 24 to 48 hours after ovlulation of primary oocytes. To date there is no reliable, practical method for determining this day. However, studies have shown that normal sperm will retain their capacity for fertilizing eggs within the uterus of the bitch for at least four to six days. Thus, we should be able to put together a breeding program based on these facts.

When to begin breeding is perhaps the most critical and frustrating decision in any breeding program. Many breeders recommend breeding based on the behavior of the male stating that "my stud dog will only breed on the correct day." However, studies have demonstrated that typically stud dogs are willing to breed to any bitch in standing heat. The color of vaginal discharge has also been suggested as the key factor to determine when to breed, that the optimal time to breed is when the vaginal discharge changes from bloody to a translucent yellow or straw color. This approach is totally incorrect as normal bitches have been observed never to have a bloody discharge, while others may bleed throughout standing heat. Turgidity of the vulva is too subjective an approach to be consistently effective. Thus, even though the vulva changes from being tense and turgid to being soft and pliable as the bitch progresses from proestrus to estrus, it is simply too subjective an approach.

Vaginal exfoliative cytology provides a good reflection of rising plasma estrogen concentrations. A full estrogen effect is seen on cytology as greater than 80 percent epithelial cells being of the superficial type, with no neutrophils present on the smear. This would be a smear characteristic of a bitch in standing heat. But, it is important to note that this type of vaginal smear may precede, or, less commonly, lag behind the onset of behavioral estrus. Therefore, vaginal cytology is an excellent guideline for determining proper breeding dates, BUT IT IS NOT PERFECT.

Perhaps the best indicator of when to breed is found in the behavior of the response of the bitch to the stud. On day five or six of proestrus, the bitch should be muzzled and brought into contact with the male for ten or fifteen minutes. Allow the male and female some freedom of movement and if the female stands for the male, breeding should begin regardless of any other observations.

Thus, we can make the following recommendations concerning breeding:

1. Record the fist day of vulvar swelling, bloody vaginal discharge, and when the male shows obvious interest in the bitch;

2. Begin "teasing" the bitch with a male dog on day 5 or 6 of the proestrus and repeat this process every two days to determine the first day of standing heat;

3. Allow the bitch to be bred, beginning on her first day of acceptance of the male, and continue to breed every two days throughout the acceptance period;

4. Complete records should be kept on the dates of proestrus, breeding, and smears. Notes should be made on the presence or absence of ties, the length of the tie, and the behavior of both the male and the female. Records should also be kept on whelping dates, litter size, health of puppies, length of parturition (total birthing process), interval between births, and any other pertinent information.

Nature being a curious thing, there is no absolute guarantee of conception, but using these tips as a guide your chances may be improved. Good luck!