Canine Fetal Development Research Paper
Canine Fetal development
In the majority of female dogs parturition occurs between 64-66 days, after the ovulatory surge. Using the date of mating as a reference point as observed in cases of just a single mating or insemination, birth can occur as early as 56 days later and as late as 68 days later.
Part of the explanation is that dog sperm in some cases, survive in the dogs tract for up to 7 or 9 days and still remain viable in terms f being able to achieve fertilization and result in pregnancy. It is possible that in dogs as in other species, many sperm die or loose fertility after 1 or 2 days. However, the number that retains fertility for 2 days is sufficiently high in dogs that mattings do not affect fertility and fecundity on the day of the LH surge, 2 days before ovulation. Thus, in such pregnancies, the sperm survived 2 days before potentially penetrating the oocyte, and the chromatin had to survive another 2 to 3 days to function as a male pronuclear, which fuses with the female pronuclear to form the 1-cell zygote. Fertility declines with mating’s …show more content…
During this time period, there is uterine swelling around the placental sites that feels like firm and discrete lumps. After 30 days, the uterine swelling is more diffuse and it is difficult to distinguish the gravid uterus from the feel of the intestinal tract. Dogs that are very large or obese may be difficult to examine in any stage, however.
A third way to detect pregnancy is by taking x-rays. Fetal skeletons can be visualized at about 45 days of pregnancy. This test cannot be done until late in gestation, but it is nice to know about how many of the little creatures you can expect once the actual birthing occurs. After 57 days the fetus has completed prenatal development and is ready to be born, whelping is imminent from this point
In the majority of female dogs parturition occurs between 64-66 days, after the ovulatory surge. Using the date of mating as a reference point as observed in cases of just a single mating or insemination, birth can occur as early as 56 days later and as late as 68 days later.
Part of the explanation is that dog sperm in some cases, survive in the dogs tract for up to 7 or 9 days and still remain viable in terms f being able to achieve fertilization and result in pregnancy. It is possible that in dogs as in other species, many sperm die or loose fertility after 1 or 2 days. However, the number that retains fertility for 2 days is sufficiently high in dogs that mattings do not affect fertility and fecundity on the day of the LH surge, 2 days before ovulation. Thus, in such pregnancies, the sperm survived 2 days before potentially penetrating the oocyte, and the chromatin had to survive another 2 to 3 days to function as a male pronuclear, which fuses with the female pronuclear to form the 1-cell zygote. Fertility declines with mating’s …show more content…
During this time period, there is uterine swelling around the placental sites that feels like firm and discrete lumps. After 30 days, the uterine swelling is more diffuse and it is difficult to distinguish the gravid uterus from the feel of the intestinal tract. Dogs that are very large or obese may be difficult to examine in any stage, however.
A third way to detect pregnancy is by taking x-rays. Fetal skeletons can be visualized at about 45 days of pregnancy. This test cannot be done until late in gestation, but it is nice to know about how many of the little creatures you can expect once the actual birthing occurs. After 57 days the fetus has completed prenatal development and is ready to be born, whelping is imminent from this point