How to determine the onset of childbirth in a dog?

Ultrasonography can help determine the number of days to delivery by measuring the biparietal head diameter of the fetus and using a special scoring formula in dogs of different sizes.

From the 42nd day of pregnancy, the fetal skeleton becomes visible on radiographs, from the 45th to 49th day the bones of the skull are visualized, from the 57th to 59th day – the bones of the pelvis, from the 58th to 63rd day – the teeth.

2 to 7 days before delivery, dogs may begin to show symptoms of excitability, restlessness, nesting, increased urination and defecation, and reduced appetite.

This is due to the gradual increase in uterine contractions. On the day of delivery, appetite may be completely absent.

Breast enlargement begins in the second half of pregnancy. Lactation in some bitches appears from the 40th day of pregnancy, in some just before childbirth, during them or immediately after.

An increase in the concentration of the hormone relaxin in the blood leads to an increase and softening of the loop (0–2 days before delivery), relaxation of the cervix and, as a result, separation of the mucous plug (0–7 days before delivery).

A drop in body temperature before delivery is a reliable indicator of the onset of labor in dogs, reflecting a rapid drop in blood levels of the hormone progesterone below 1 ng/mL, the thermogenic hormone that maintains pregnancy. Body temperature drops sharply (to about 36,7–37,7 degrees).

You should know that after the fall, the temperature will rise slightly (up to about 37,2 degrees) and will be maintained throughout the first stage of labor. At this time, 8-24 hours remain before the appearance of the first puppy.

It is recommended to start measuring rectal temperature from the 54-55th day of pregnancy 1-2 times a day at the same time.

A slight decrease in body temperature may occur in the last week of pregnancy, as the level of progesterone in the blood gradually decreases. However, in some dogs, it is not possible to fix the moment of temperature drop in this way.

The rupture of the first amniotic sac, the outflow of yellow-green discharge (water) from the external genital organs indicates the separation of the placenta and the beginning of the second stage of labor (the stage of attempts – the expulsion of the fetus); and before the appearance of the first puppy, 1-2 hours remain.

November 2, 2017

Updated: July 6, 2018