So you think you want to breed?




Dog reproduction


Often we get asked questions by clients who are considering having the one litter.  It is a good idea to have some basic idea about the process.

The Oestrus cycle refers to the stages of the reproductive cycle in the female.

These are:

  • proestrus, is the time at the start of heat (or fertile period) . There is vaginal bleeding, swelling of the vulva and attractiveness to males.  Usually lasts on average of 10 days.
  • oestrus, is when ovulation occurs.  The bitch will stand for the dog and the vaginal discharge may turn straw coloured or pinkish.  It usually lasts 5-9 days.  The vulva changes from turgid to soft &  Matings during this time are most likely to result in pregnancy.
  • metoestrus is the end of heat,  the bitch no longer accepts the dog and the vulva returns to normal.
  • anoestrus is the period between heats, which can last between 7 and 13 months, although the average is 7 months.


A bitch’s first heat is normally between 6 months and 23 months.  It is generally when they have reached their adult weight and height, so the larger the breed, the later the onset of oestrus  The majority will have had their first heat by 12 -14 months.  They generally have 1-2 heats per year.  Regardless of when they start to ovulate, a bitch should not be breed before 18 months of age.


Because of the time between heats, it is important to try and determine when ovulation occurs, to increase the chances of a fertile mating.  On average, a bitch ovulates 12 days after the start of  proestrus (vaginal bleeding) and should be mated from day 14 onwards.  While changes in vaginal discharge colour, vulval swelling and behaviour change occurs proestrus to oestrus, these changes are not always reliable.  The blood level of the hormone progesterone increases with ovulation.  Measuring this with a simple blood test is a more reliable way of determining ovulation.  We can do this in house.


Pregnancy diagnosis is best done by ultrasound at around 28 days gestation.  The gestation period (length of pregnancy) is, on average 63 days.  It is recommended that vaccination occurs BEFORE mating, worming should be done before, during pregnancy and after birth.  There is no need to increase the amount of food given for the first 30 days, but it should be gradually  increased in the last half of pregnancy.  The bitch should be fed a balanced, good quality food, often divided in 2 -3 smaller meals to accomodate her reduced stomach volume.  It is not recommended to supplement the diet with calcium, Vit D or other vitamins.  The second and third week after birth are usually the times of greatest nutritional need for the bitch, and she may need twice what she would normally eat to feed the pups.  She needs several small meals and time to eat without the pups bothering her  Exercise should continue through pregnancy, depending on the bitch’s tolerance.

There are a couple of ways to manipulate the breeding cycle.  A injection of proligestone (Covinan) can be given to delay or suppress heat if given during anoestrous or proestrus.  This  should not be given to bitches in their first heat, and pregnancy can still occur if they are mated within a few days after the  injection.

choose your pet's partner carefully
Choose your pet’s partner carefully


Alizin is an anti-progesterone injection which can be given to cause abortion in the event of a mismating.  Two injections are given 24 hours apart.  It is effective from early pregnancy ie. the day of mating.