How long can a dog be pregnant to have a puppy?

There are many methods to diagnose pregnancy in bitches. At present, the commonly used methods are external observation, rash examination, ultrasonic detection, hematological examination, urine examination and so on.

External inspection method

About a week after mating, the vagina begins to contract, and a small amount of dark-brown liquid can be seen, resulting in loss of appetite. At 2-3 weeks of pregnancy, the breasts begin to increase gradually, the appetite increases greatly, the coat is bright, the temperament is docile, slow, steady, and careful. A small number of bitches will have pregnancy reactions for a period of about 25 days of pregnancy, sometimes vomiting, loss of appetite, and some partial eating. A month or so, it can be seen that the abdomen is dilated, the breast is prolapse, the nipple is elastic, the mammary gland is gradually enlarged, and even the milk can be saved, the weight increases rapidly and the frequency of urination increases. 50 days later, "fetal movement" can be seen on the ventral side, and the heart sound of the fetal dog can be heard in the abdominal wall with a stethoscope. The disadvantage of external observation is that people without experience cannot early judge whether the bitch is pregnant or not.

Touch rash test

When the bitch is about 20 days pregnant, the uterus begins to become enlarged, and the diameter of the uterus can be clearly sensed by touch on the abdominal wall, but it takes someone with considerable experience to make a more correct diagnosis. After 25 days of pregnancy, the fetus can be touched (such as a flexible meatball the size of an egg). Attention should be paid to the difference between touching and inelastic dung. When touching, use the hand to slide back and forth outside the abdominal wall above the last two pairs of nipples, avoid rough and excessive force, so as not to cause miscarriage.

Ultrasonic detection method

At present, the commonly used are Doppler instrument, A-type ultrasonic instrument and B-type ultrasonic instrument.

Doppler examination can be used to detect the heartbeat of fetal dogs at 19-25 days of pregnancy. With the development of fetal dogs, the accuracy increased, the accuracy of 36-42 days of pregnancy was 85%, the accuracy of 43 days of pregnancy to the end of pregnancy was 100%, and the accuracy of non-pregnancy was 100%. Bitches that are too small have a slightly higher misdiagnosis rate due to the beating of the abdominal artery.

Type A ultrasound examination can be used for the diagnosis of pregnancy after 18-20 days. At 32-60 days of pregnancy, the accuracy is 90%, and the accuracy of non-pregnancy is 85%. When using this examination method, the signal from the bladder filled with urine should be distinguished.

The effect of B-mode ultrasonic examination is better than that of Doppler instrument and A-type ultrasonic examination. Its advantage is that it can detect 18-19-day-old fetal dogs, and even identify the sex, number and life or death of fetal dogs.

X-ray examination

The shape of the uterus can be seen on the 30th to 35th day of pregnancy, and the contrast can be seen in the skeletal changes of the fetal dog on the 49th day. When a few bitches were examined by X-ray on the 40th day of pregnancy, the vertebrae and ribs of the fetal dogs were clearly visible. When using this method, 200-800 milliliters of carbon dioxide must be injected into the abdominal cavity according to the size of the bitch.

Blood test method

The blood composition of the bitch changes during pregnancy. According to the changes of these parameters, we can judge whether the bitch is pregnant or not, and can distinguish pregnancy from false pregnancy.

From the 21st day of pregnancy, red blood cells begin to decline, and by the last week of pregnancy, 70% of bitches can be reduced to 5 million / ml, red blood cell volume decreased by 40%, and hemoglobin ratio decreased, especially in young and improperly raised bitches. ESR increased to the maximum at delivery. From the 20th day of pregnancy, the red blood cell volume continued to decline to a minimum of 30 before delivery, compared with 45 in non-pregnant bitches. From the 21st day of pregnancy, the platelet increased, reaching 500000 / ml before delivery, and the white blood cell increased to the maximum on the 49th day, then decreased, but it was abnormal when it was more than 30000 / ml. During 28-42 days of pregnancy, the concentration of clotting factor increases until it decreases during delivery. Fibrin increases 2-3 times during pregnancy. On the 21st day of pregnancy, the level of serum creatinine decreased by 25%, 0.8mg / L and 1.1mg / L, respectively, and serum protein C decreased by 40% 45%. The average level of serum creatinine was 648mg / L in postpartum bitches and 1108 mg / L in parturient bitches.

Urine test

5-7 days after pregnancy, a hormone similar to human chorionic gonadotropin appears in the urine of dogs, so the human "quick-acting pregnancy test" can be used to test whether the dog urine contains substances similar to human chorionic gonadotropin. If the test is positive, it is pregnant, and the negative is not pregnant. The accuracy of this method is so high that it can be detected about 6 days after mating.