How Good Is a Dog's Reproductive Ability? A Detailed Look at Canine Reproductive Characteristics
Reproductive Ability
Dogs reach sexual maturity before 1 year of age and show signs of estrus (commonly known as "heat"), but the timing of physical maturity varies depending on the breed. Generally speaking, small breeds reach physical maturity earlier than large breeds. For small dogs such as the Pekingese and the Shih Tzu, it is advisable to breed and conceive at the second estrus (around 12-14 months of age), while for the Great Dane, the German Shepherd and others, breeding after 18 months of age is better, because by then they have reached physical maturity.
The time of highest conception rate is on the eleventh to thirteenth day of the female dog's estrus. After conception, the female dog gives birth after a gestation period of 64 plus or minus 4 days, and the nursing period after birth is about 45 days. The average litter size for a female dog is 4-6 puppies, with differences depending on the breed.
Difficult birth mainly occurs in the following situations: the fetus is large, especially when only 1 fetus is carried; the female dog becomes pregnant before reaching physical maturity, and the pelvic opening is narrow; the female dog is fed mainly on meat, and bone development is poor; the fetal position is abnormal; the female dog is weak and uterine contractions are insufficient; and premature birth caused by external stimulation before the normal time of birth. Sometimes, a female dog of a small breed being too small in size while the male dog is too large is also one of the factors causing difficult birth. From 7 to 14 days after birth, the puppies open their eyes. Puppies rely on smell to find the female dog's nipples to nurse, and the female dog also relies on smell to identify her own puppies. Seven days after birth, the puppies enter a rapid period of growth and development, which can easily cause or worsen postpartum calcium deficiency in the female dog, manifesting as panting, high fever (around 40°C) and convulsions, and calcium should be supplemented promptly.