The gestation period for dogs is around sixty-three days. Just like in humans it varies from pregnancy to pregnancy, but rarely by more than a week. Different breeds of dog have the same length of gestation as each other, although larger dogs seem to go over a little bit and smaller dogs are a little bit early. Dogs reach sexual maturity at differing ages depending on the breed. Small breeds may reach sexual maturity at as young as six months, but larger breeds may take up to two years. Both bitches and dogs mature at the same rate.
Bitches cycle throughout their lives, and do not experience a menopause. They can get all the reproductive diseases associated with humans such as breast and uterine cancer and infections.
Bitches are able to become pregnant during their estrus; this usually occurs twice a year and lasts between five days and two weeks depending on the dog. The most common sign of this is a small amount of blood, but this can be missed as the dogs clean themselves.
If the bitch becomes pregnant then there will be no signs for up to five weeks, unless the dog is a small breed and has more than one puppy. By four weeks a vet should be able to palpate the abdomen and say whether the dog is pregnant. After five weeks the abdomen steadily grows and the pregnancy becomes obvious. The exact size that the dog reaches will depend on the breed and the number of puppies being carried.
Towards the end of the pregnancy the bitch's nipples will swell and become red, in readiness for milk production. It is a good idea to allow the bitch to sleep where you plan to let her have and keep her puppies so that she gets used to the environment. Any form of box that is large enough will do. Before the puppies this can be left open on one side, once they are born it is a good idea to erect a small barrier across the opening that the mother can hop over, but not the puppies.
No supplements are necessary during pregnancy if the dog is being fed a good all round balanced food, providing supplements is more likely to unbalance the diet. The mother to be needs more food for the last three weeks of the pregnancy, but has a smaller stomach capacity than before, so should be offered smaller meals more frequently. As the mother to be becomes larger she becomes less mobile and may become grumpy.
When labor is approaching the dog will start to exhibit "nesting" behavior, she will go off her food and become restless, and may vomit. Once whelping commences the bitch will be in obvious discomfort and will turn towards her tail region and flank region. Some clear discharge may be evident. The dog's rectal temperature drops markedly and some professional breeders use this method to predict labor. Once contractions start then the first pup should be born within one or two hours. This will be shorter for dogs that have had puppies before.
When the puppy is born it may or may not be covered in membranes, each puppy has its own membrane sac and placenta. The mother will clean this off and cut the umbilical herself; if she is a first time mother some help may be needed. The cleaning of the pup by the mother stimulates defecation and urination and, if assistance is required, as well as making sure the membranes are clear of the nose the pup should be rubbed gently with a towel to replace this. It is perfectly normal for the mother to eat the placenta but some people prefer to stop this as it may cause an upset stomach in the mother. Up to half of all puppies are born tail first and this is no cause for concern if everything proceeds normally.
Labor recommences after between fifteen and sixty minutes. It is important that the mother is kept in a calm environment before, during and after whelping to familiarize herself with her puppies. When the last puppy has been born the contractions stop and the mother settles down.
The vet is not needed for a normal birth but you should have a number ready in case of problems. If the pregnancy has gone more than sixty eight days and there is no sign of labor get the bitch checked. Once labor starts the vet is needed if contractions for the first puppy last for more than an hour without signs of a puppy, after the first puppy contractions should not last more than half an hour without a new puppy. Each puppy should have its own placenta; see the vet if one is "missing". If a puppy becomes stuck call the vet. Labor should not continue for more than twenty- four hours. Once the puppies are born all discharge should stop within two weeks. If it continues, or is an unusual color or smell see the vet.