Female Dog Heat Cycle & Pregnancy: What to Expect

May 10, 2026

If you're considering breeding from your female dog, understanding her reproductive cycle, pregnancy and the stages of labour can help you know what to expect along the way.

In this guide, we'll look at the female dog heat cycle, canine pregnancy, the three stages of labour, pregnancy nutrition and natural support for the bitch and her puppies.

Understanding the Female Dog Heat Cycle

The canine heat cycle generally lasts around 18–21 days.

Intact female dogs usually come into heat approximately every six months, although individual dogs can vary.

The female dog's reproductive cycle has four stages:

Proestrus
Estrus
Diestrus
Anestrus

Proestrus

Proestrus is the first stage of the reproductive cycle and lasts for approximately nine days.

During this stage, female dogs begin to attract males, although they will generally reject their advances until they reach the next stage of the cycle.

Signs of proestrus include:

Swelling of the vulva
Bloody discharge

Estrus

Estrus is the stage when the bitch is receptive to the male.

This stage can last anywhere from 3–4 days to 7–11 days, so there can be quite a bit of variation between individual dogs.

Diestrus

Diestrus is the final stage of the active heat cycle and typically occurs around day 14.

During diestrus, the bitch's discharge becomes redder and gradually tapers off. The vulva returns to its normal size and she will no longer permit mating.

The heat cycle is complete once the signs of swelling and discharge have disappeared.

Anestrus

Anestrus is the period between one heat cycle and the next.

This stage usually lasts around six months before the female dog comes into heat again.

How Long Are Dogs Pregnant?

Normal gestation for dogs is approximately 63 days from conception, although this can vary between individual dogs.

A normal pregnancy can range from around 58–68 days.

Like people, dogs are pregnant for three trimesters, with each trimester lasting approximately 21 days.

The Three Stages of Labour in Dogs

When your bitch is getting ready to give birth, there are three stages of labour to be aware of.

Stage One: Early Labour

Stage one generally lasts around 12–24 hours and is often not outwardly noticeable.

During this stage, contractions in the muscular wall of the uterus gradually increase in both strength and frequency. However, visible contractions are not usually evident yet.

Instead, you may notice changes in your dog's behaviour.

Signs of labour in dogs can include:

Change in disposition and behaviour
Restlessness
Reclusive behaviour
Intermittent nesting
Refusing to eat
Vomiting
Panting
Clear vaginal discharge

Stage Two: Puppies Are Delivered

Stage two is when the puppies are delivered.

This stage can take anywhere from 1–24 hours, with the bitch delivering one puppy at a time.

Each delivery should not last more than 1–2 hours, with puppies normally arriving every 30–60 minutes.

Stage Three: Delivery of the Placenta

Stage three is when the placenta is delivered.

Stages two and three actually occur at around the same time, with the placenta usually being delivered shortly after each puppy.

Stage three is complete once all of the placentas have been delivered.

If your dog's labour takes more than 24 hours, or if more than 2 hours pass between puppies, contact your veterinarian. This could be a sign of a serious complication, and both the bitch and unborn puppies' lives could be at risk.

Feeding Your Pregnant Dog

Good nutrition is particularly important during pregnancy as your bitch needs to support not only herself but also her developing puppies.

We recommend providing your pregnant dog with a nutritious, fresh food diet abundant in protein, healthy fats, vitamins and minerals.

Although there may be days when her appetite wanes, pregnant dogs typically consume approximately 1.5 times more food than non-pregnant dogs.

Be prepared to increase her food intake as needed. She may also prefer smaller, more frequent meals. It's important she receives adequate nourishment to support the development of healthy puppies.

Additional supplements can be introduced to boost her mineral and vitamin intake, such as Greenpet Essentials.

For more information, see our guide to feeding a natural diet for dogs.

Natural Support for Your Bitch

There are a number of natural supplements that may help support your bitch before, during and after whelping.

Raspberry Leaf

Raspberry leaf can be brewed into a tea and given before, during and after whelping, commencing from the time she is on heat until she has weaned her litter.

Herbal Supplements During Pregnancy

Herbal supplements may be used during the last trimester of pregnancy. For recommendations specific to your bitch, please contact the Greenpet clinic.

Marshmallow Root

Marshmallow root may be brewed into a tea as a natural way to support milk production.

Greenpet Essentials

Greenpet Essentials is a natural nutritional and mineral supplement that can provide additional nutritional support for the bitch.

Natural Support for Newborn Puppies

Once the puppies arrive, you may also want to have some natural products on hand to support them through their first weeks.

Goat Milk Powder

Natural Animal Solutions Goat Milk Powder may be used if the bitch's milk supply is low or she is unable to feed her puppies.

It can also be used during weaning if necessary.

Colostrum Powder

Greenpet Colostrum Powder can provide additional support for puppies that are in poor health and may help support their immune system.

Preparing for a Healthy Litter

Breeding your dog involves much more than the mating itself. Understanding her heat cycle, providing good nutrition during pregnancy, knowing what to expect during labour and being prepared to support newborn puppies can all help you feel more confident throughout the process.

If you're considering breeding from your bitch, we highly recommend Let's Have Healthy Dogs. It covers: