submitted with permission by Marj Brooks
with thanks to Kevin & Donna Frizzell of DeSaix St. Bernards for generously allowing us to use many of their superb array of articles
As well as changes in the bitch as noted by the owners there are some clinical methods of pregnancy diagnosis:
Palpation: Palpation of the abdomen can be a good indicator of pregnancy. This should only ever be undertaken by a qualified veterinarian who has good practice with this technique to avoid the risk of damage to the developing young. Palpation is only considered a successful indicator if carried out between the 25th and 30th day. After this time the foetus is surrounded by too much fluid to be able to distinguish it and the uterus has also become softer and less identifiable through palpation. Palpation is easiest on a small dog carrying a large litter and difficult on an overweight, well muscled or large bitch. The whelps will feel like small marbles slipping through the fingers or a water balloon with knots tied at regular intervals.
Ultrasound: Pregnancy can be diagnosed as early as 21 days gestation but is more accurate at four to five weeks. It may not give an accurate report of the numbers of whelps but can at least confirm or deny pregnancy and the presence of viable foetuses. There are a lot of misconceptions about ultrasounding. Speaking from experience we have had 100% accuracy with all ours to date. It doesn’t matter if the bitch has an empty or full bladder prior to having the procedure done. It is non invasive but does require a section of the underbelly hair to be shaved. We ultrasound all our bitches for pregnancy confirmation to allow us to book leave and organise other commitments in advance.
X Rays: X-Raying is useful for conducting a head count rather than pregnancy diagnosis as by eight weeks gestation its pretty obvious that the bitch is pregnant in most cases. It is not worth attempting to X-Ray prior to this time as the foetal skeletons have not calcified sufficiently to be able to be detected by X-Ray. X-Rays are not always 100% accurate in the case of large litters.
Blood Tests: At this stage there is no definitive blood test that can be carried out with accuracy on the bitch. It is not possible to check Progesterone as Progesterone is secreted for 49 days by the corpus luteum if there is no pregnancy and for the duration of the pregnancy if the bitch is pregnant. There have been developments by ICG with the testing of a blood protein at around 30 days but inflammatory or infectious processes can give a false positive result. By this stage the bitch can be ultra-sounded without the invasiveness of a needle.