All domestic dogs are descended from the Grey Wolf. It is thought to be the first animal to have been domesticated by man and has been used for hunting, herding livestock and as a companion animal over the last 15,000 years.
The various breeds of dogs that we have today, ranging in size from the tiny Chihuahua to the Great Dane are all of the same species. Each breed has developed its own physical and behavioural characteristics due to selective breeding by humans but they are all, at heart, the same.
Dogs are pack animals and need companionship, either human or animal. They become sexually mature from around 6 months of age and can breed successfully for their whole lives. The gestation period is 56-72 days and puppies are weaned at around 6-8 weeks old.
Bitches (female dogs) generally come into season twice a year. They are prone to developing false pregnancies if they do not become pregnant during the season.
Dogs are used for a wide variety of purposes today, although the majority of them are kept as companion animals. Many of the jobs that different breeds where originally developed for have died out.