As a stud dog owner myself I have been asked MANY times when the best day to mate a girl is. If only it were that simple! In some cases it is, but an experienced breeder will understand that girls are rarely that straight forward!

The old rule of thumb to breed on days 9 and 11 after heat starts works fine for only about half the bitches out there, but what about the rest? In practice about half of all bitches fail to show an obvious bloody discharge to mark the start of the heat (pro-estrus). A vaginal smear is a useful way of establishing where a girl is at in her cycle.

A vaginal swab is all that's required. Cytology is a quick, non-invasive test, I firmly believe that a happy, relaxed bitch has a far better chance of becoming pregnant. I would advise against stressing out a girl with invasive tests if she is not comfortable and co-operative.

The canine estrous (reproductive) cycle is made up of 4 different stages. These are proestrus, estrus, diestrus, and anestrus. Each stage has differing signs related to behavior, physical or clinical changes, hormonal changes, physiologic changes, and cytologic (vaginal smear) changes.