The Bitch's Oestrus Cycle: "Coming on Heat", "In Season"

A bitch may reach sexual maturity anytime from 6 to 12 months of age and this is indicated by the first oestrus cycle, more commonly referred to as "coming on heat" or "coming into season". From this initial season, bitches come on heat every six months (for most bitches), and each oestrus period lasts about 18 – 21 days, but this differs from dog to dog, and it can vary from 14 – 28 days.

During this time, the ovaries produce a crop of eggs and the bitch becomes fertile, capable of becoming pregnant if mated at the correct time. Associated with this is a discharge from the vulva, a swelling, a probable behaviour change as a result of altered hormone levels, and she will become extremely attractive to male dogs.

On average, in the first stage of heat, the vulva will begin to swell and there will be a blood-stained discharge, your bitch will usually be interested in the males which are attracted at this time but will not accept them for mating. This stage usually lasts for about 9 days. In the second stage, often specifically referred to as the heat phase of the oestrus cycle because the female is actually receptive to mating and will stand for the male in order to do this. The vulval discharge is no longer blood-stained, but rather a straw colored discharge. Conception can only occur during this stage, which lasts anywhere from 6 – 12 days, (usually the former). The third phase of the cycle is signified by a subsiding of the whole process, as the vulva returns to normal, males will cease to be attracted by the bitch and she will not accept any males for mating. This usually takes around 30 days and it is followed by a period of rest for the reproductive system until the next heat.

It must be stressed that the oestrus cycle varies enormously between bitches in terms of behaviour outward signs and duration; we have only described a generalized case, so do not expect your bitch to follow this exactly, rather, use it as a guideline to understanding your own bitch.

If you do not wish to mate your bitch during a heat she MUST BE SEPARATED FROM MALES FOR THE DURATION OF THE ENTIRE SEASON, excluding the resting phase of course. Make sure your yard is dog proof and keep her on a leash whenever she is outside your property. Should you be considering mating your bitch in the future then it is imperative that you look into this very carefully and discuss it fully with your veterinarian first so you are aware of, and understand the requirements and procedure before you undertake it. It would be helpful to keep note of your bitch's own characteristic oestrus cycle so that if you wish to mate her in the future you can use this as a guide for calculating the correct time for mating. I do not wish to go into any further details regarding mating, pregnancy and whelping because this is an important and serious area which would be better dealt with by experts and professionals.

Neutering Health and your Siberian