The Adolescent Dog

With the passing weeks the young puppy naturally grows into a young adult. As a generalization, one year of a dog’s life is taken to be equivalent to seven human years, although  a six-month-old pup of medium  size is probably  nearer  the physical age of a ten to twelve-year-old  child, and in a state of early puberty; in some cases a bitch may soon come on heat. The larger the breed, the later the onset of physical and sexual maturity. Bones grow in length from areas known as growth plates; while growth is still taking place the plates are said to be open, and as the period of growth comes to an end, the plates are said to close. This closure takes  place as early as seven months  in a dog the size of a Miniature Dachshund, but does not happen  until fourteen  or fifteen months  in an Irish Wolfhound . A bitch  puppy  in the smaller  breeds  may come on  heat at six months,  while man y of the giants will be eighteen months old before it occurs.

A bitch can be mated and become pregnant at her first heat, and precautions taken against unwanted  pregnancies. Most breeders advocate against in-z from a bitch as early as this on the grounds  that it may stunt growth. At the other end of her life, the bitch does not cease producing eggs from the ovaries , she will continue to come on heat and be capable of mating and bearing puppies  into  what would be considered  late middle and even old age  in the human. Occurrences of twelve-year-old   bitches  whelping  naturally,  though with small litters,  are not rare.

The male dog is often ready and willing to mate at six months, and it would he unwise to rely on his inexperience and youth if he gains access to a suitable bitch; even his own mother  is not safe from amorous attentions. At the other end of the scale, dogs have sired  litters  well into  their teens, which  possibly accounts for the phrase that ‘there’s life in the old dog yet’. Generally, if pups are not wanted,  they must  be prevented;  no benefit, but sometimes  harm,  is derived from letting a young bitch have a litter, or allowing a sexually overeager male to mate in order  to cool him down.  Dog  breeding  is time-consuming, costly, and fraught  with complications,  and  best left to professional  breeders (see also Reproduction and  Mating, 
A bitch can be prevented  from mating through  neutering or contraceptive pills and injections. She can also be confined while she is on heat, and the best place is often a reliable  boarding  kennel.  If, in spite  of such  precautions,  a female and male dog are caught in ‘incriminating circumstances’, pregnancy can  be prevented  with a hormone  injection  within  the first day or so after mating. This  must be regarded strictly as an emergency measure; an y upset of the hormone  balance may lead to problems  in the  uterus.