How does it all work? The processes of birth are regulated mainly by the timely secretion of hormones from the pituitary gland (posterior portion) into the bloodstream of the bitch. This gives rise to uterine contractions intended to propel the puppies through the vagina and vulva.
As the fluid pressure within the uterus increases, and when the pituitary hormone secreted into the bloodstream sends the uterine muscles into a series of contractions, the allantoic sac of the first puppy to be born is pressed and squeezed against, and eventually protrudes through, the dilating cervix. Some puppies come head first (anterior presentation), others come tail first (posterior or breech presentation). When, in this position, the puppy lies on its back, the presentation is known as lumbo-pubic. Quite frequently the two positions alternate so that an anterior presentation is followed by a posterior and vice versa.
In young bitches the first puppy may take some hours to make its appearance. In older bitches that have borne litters, parturition is more rapid unless there is an obstruction.
The chief impediments with dog breeding are:
(a) a head that is wider than the pelvic girdle;
(b) a head turned back upon the shoulder or jammed beneath the pubic brim;
(c) an oversize puppy or one with an enlarged (dropsical) abdomen or a hydrocephalus (fluid in the skull) ;
(d) a posterior presentation, often with the head of the next puppy also in the vagina;
(e) doubling of the body of the puppy with the head and hindquarters retained;
(f) two puppies, side by side.
There are many other possible complications but these are the most common, and each needs professional assistance.
The general rule in dog breeding is that there shouldn’t be more then 1 hour between 2 puppies without checking with a veterinarian. They don’t have to be your regular vet there are plenty of emergency centre around that can give you advice over the phone.
If you leave it too long the remaining puppies could suffer.
Make sure the puppies that are already out start succeling. Milk stimulation with produce hormones that will help with the contractions.
If you are new to dog breeding and it is your first time that you assist a dog with welping. I would recommend that a few days before the puppies are due you go and talk to your vet to come up with a plan of action.
In some breeds it might be useful to Xray the bitch in the last week and know exactly how many puppies you are expection.
If you are dealing with a brachocephalic breed( bulldog, pekinese, etc) or a chihuahua were puppies have large heads. We recommend you consider doing an elective cesearian not to wait for trouble that is most likely coming your way