When to mate: the four stages of a bitch's season

Breeding dogs is not always a straightforward process. When problems occur they can put at risk the health of the parents and puppies, and can affect the future breeding ability of the dog or bitch. Getting the mating right — at the right point in the season, with a healthy male, with a bitch who is actually in her window — is the first thing that has to be right.

Below is what I look for, in the order I look for it.

The four stages of the fertility cycle

Proestrus is the initial stage of your dog's season. It lasts around 10 days but each dog may vary. Signs can include behaviour changes, bloody discharge, swelling of the vulva, and interest from male dogs.

Estrus is the second stage, and will typically occur some point within day 10 to day 28. This is her optimum time to be mated. Signs include showing more interest in males, a pinky discharge from her vulva, standing still, and tail flagging in response to back pressure.

Diestrus is the third stage and is when her fertility is starting to decline. Signs include more of a return to normal behaviour, a slight bloody "cleaning" discharge from her vulva, and less interest in males.

Anestrus is the rest period, as her body returns to normal before starting to prepare for her next season.

Your dog will be most fertile during her estrus phase — but this optimum period may only be for a few days in the time scale between proestrus and diestrus.

The split season — a warning

A split season is when your dog starts her fertility cycle but doesn't quite reach the estrus stage. Her progesterone levels rise as normal but then drop before reaching their peak. This can be misleading if a blood test for progesterone is used to predict the time to mate, unless it is repeated nearer the predicted time (which means another blood test).

If your dog has a split season there is a good chance she will start her cycle again in three to four weeks' time.

Why I use cytology

Cytology is the examination of single cells. By examining the tissue under a powerful microscope, information can be decoded as to how close a bitch is to being ready to be mated.

It does not involve an invasive blood test as for progesterone testing. Instead it consists of collecting cells from just inside her vagina, taken with a small cotton swab.

The procedure takes a few seconds and is painless. Once the swab is taken it is allowed to dry and prepared for examination with a special dye.

Under the microscope the four main cell types can be seen. Their frequency, positioning and appearance will indicate how far along her fertility cycle your dog is. By the correct reading of these cells, it can be determined whether she is in early season, ready to mate, past ovulation, or even having a split season.

The appearance of the cells from the swab will show where in her cycle your dog is in readiness for her mating, and can be repeated easily as to pinpoint the optimum time for natural or AI mating.

The benefits of cytology, in practical terms

• The exact timing of ovulation can be pinpointed in readiness for mating.
• The test takes a few seconds and results are ready in five to ten minutes.
• Swabs can be taken at several points during your dog's cycle and are painless and stress-free.
• Cytology is also a way to screen vaginal health, so it can identify bacterial infections before external signs can sometimes be noticed.

When to take the first swab

Regarding the timing of cytology swabs, I would recommend taking the first swab on day 5 or day 6 after noticing the first vaginal discharge and vulval swelling. This will give an indication of how far along her cycle she is.

The more swabs taken over the next few days, the more accurate the prediction for ovulation.

Why timing matters

By using a professional canine fertility service you can:

• Ensure the correct time to mate, to avoid mis-timing and failure to hold.
• Make sure the male dog is healthy and producing viable sperm.
• Identify infections in both the male and female reproductive tracts.
• Get a pregnancy diagnosis early enough to alter the bitch's diet and exercise.
• Follow the progress of the puppies inside the bitch through the pregnancy.
• Get whelping assistance if it is needed.
• Check the bitch post-whelp to ensure no puppies or placenta remain.

At Rippletrix and at the fertility clinic, every mating is timed with cytology. It is the difference between a bitch that holds and one that doesn't, and the difference — for the buyer — between a stud fee that produces puppies and one that produces a phone call to say the season didn't take.