Article in English: If you suspect that your dog is pregnant, it is worthwhile to visit the vet to confirm your suspicion. There are various methods a vet can use to definitively confirm pregnancy. The vet will examine the dog and pay special attention to gently feeling her tummy.  By palpation (feeling from the outside of her belly) the vet can sometime feel the womb and the outline of a puppy inside. However, this is much more difficult than it sounds because it is easy to mistake a puppy for feces in the bowel, and vice versa. The ideal time to feel a pregnancy is between day 28 - 35 after conception. Before this, there is not enough difference to feel to tell the vet she is pregnant. After this, the puppies can be mistaken for other things such as food in the gut. In late pregnancy (week 6 onwards), the vet can sometimes hear fetal heartbeats by holding a stethoscope to the dog’s belly. However, this is much more difficult than for human babies because of the rustling of the dog's fur coat and the fact that dogs have round, not flat, tummies. The gold standard to test for pregnancy is for your vet to run a blood test that looks for the presence of a pregnancy hormone called Relaxin.   The hormone is only reliably present after day 28 of the pregnancy. If the test is run before this date it is possible to get falsely negative results, where you believe the bitch isn't pregnant when she is.   A positive result at any point, even before day 28, does confirm pregnancy. The method that can confirm pregnancy the earliest is an ultrasound.  A skilled ultrasound operator can pick up puppies on the scanner from around day 16 onward.   In a docile bitch the scan can be done without sedation. The operator will need to clip fur on the tummy of very furry dogs so that the probe can make good contact with her skin. With the widespread use of ultrasound, the need for x-rays in pregnancy has decreased. The main reason to x-ray a pregnant bitch is in late pregnancy, to count how many puppies are present in the womb. This information is...

Summary in Vietnamese:
Tìm đến bác sĩ thú y. Khám sức khỏe cho chó. Kiểm tra nhịp đập của tim. Kiểm tra máu. Siêu âm. Yêu cầu chụp X quang.