A bitch comes into season for breeding twice in a year; the first time when she is reaching maturity, usually at the age of from seven to ten months.  Her condition will readily be discerned by the fact of an increased attentiveness of the opposite sex and the appearance of a mucous discharge from the vagina.  She should then be carefully protected from the gallantry of suitors.  Dogs kept in the near neighbourhood of a bitch on heat, who is not accessible to them, go off their feed and suffer in condition.  With most breeds it is unwise to put a bitch to stud before she is eighteen months old, but Mr. Stubbs recommends that a Bull bitch should be allowed to breed at her first heat, while her body retains the flexibility of youth; and there is no doubt that with regard to the Bulldog great mortality occurs in attempting to breed from maiden bitches exceeding three years old.  In almost all breeds it is the case that the first three litters are the best.  It is accordingly important that a proper mating should be considered at the outset, and a prospective sire selected either through the medium of stud advertisements or by private arrangement with the owner of the desired dog.  For the payment of the requisite stud fee, varying from a guinea to ten or fifteen pounds, the services of the best dogs of the particular breed can usually be secured.  It is customary for the bitch to be the visitor, and it is well that her visit should extend to two or three days at the least.  When possible a responsible person should accompany her.

If the stud dog is a frequenter of shows he can usually be depended upon to be in sound physical condition.  No dog who is not so can be expected to win prizes.  But it ought to be ascertained before hand that he is what is known as a good stock-getter.  The fee is for his services, not for the result of them.  Some owners of stud dogs will grant two services, and this is often desirable, especially in the case of a maiden bitch or of a stud dog that is over-wrought, as so many are.  It is most important that both the mated animals should be free from worms and skin disorders.  Fifty per cent. of the casualties among young puppies are due to one or other of the parents having been in an unhealthy condition when mated.  A winter whelping is not advisable.  It is best for puppies to be born in the spring or early summer, thus escaping the rigours of inclement weather.

During the period of gestation the breeding bitch should have ample but not violent exercise, with varied and wholesome food, including some preparation of bone meal; and at about the third week, whether she seems to require it or not, she should be treated for worms.  At about the sixtieth day she will begin to be uneasy and restless.  A mild purgative should be given; usually salad oil is enough, but if constipation is apparent castor oil may be necessary.  On the sixty-second day the whelps may be expected, and everything ought to be in readiness for the event.