Dog in heat

Heat in dogs happens normally once or twice a year. This is the time when female dogs are fertile and can become pregnant. Their behaviour may change during this period and they might be more likely to run away. They will bleed from the vulva and become interested in male dogs. 

Being in heat, also called being in season or estrus, is normal in female dogs who have not been neutered. The frequency of being in heat can vary with age and breed size. The heat period can last from a few days to a couple of weeks. The amount of blood changes through this period too. Take your female dog to see a vet if the signs of season don’t disappear after three weeks or if the bleeding is excessive or she seems unwell.



Understanding heat cycles in dogs

Age of their first heat:

  • Female dogs typically experience their first heat (puberty) at 7-9 months old. In some cases, up to 24 months of age. Smaller breeds tend to experience it earlier than larger breeds.

Frequency of heat cycles:

  • Heat cycles occur every 5-11 months.

Signs of heat:

  • Behavioural changes such as being over-friendly or more nervous
  • Being off food
  • Peeing more than usual
  • Swelling of the vulva
  • Bloody vaginal discharge
  • Licking back end more

Duration of the heat:

  • Typically lasts 5 to 9 days, but can last up to 20 days in some bitches.

Chance of getting pregnant:

  • The fertile period comes after the heat.
  • Timing of ovulation isn’t as simple as it may seem.
  • The ovulation can occur 3 to 6 days after the heat. But can be more unpredictable and a bitch may still be fertile after 1 week to 20 days.
  • Ovulation tests are available and are more accurate. If you are interested in breeding your dog speak to your vets.

Signs of becoming fertile:

  • Reduction in bleeding discharge and change to a lighter colour (pinkish).
  • “Flagging” behaviour, in which she keeps her tail to the side to allow mating and is willing to be mounted.
  • If your dog mates, record the date. This helps to monitor the length of the pregnancy, plan for birth, prevent pregnancy complications, or decide the best option for pregnancy termination.

Breeding or neutering?

  • From your dog’s point of view, there are no benefits to having puppies. So unless you are certain you would like to breed, you understand the responsibilities, including proper care during pregnancy, labour, and the commitment to finding suitable homes for the puppies, and are fully prepared regarding the time and costs involved, it’s best to have your bitch spayed.
  • Neutering stops heat cycles, prevents unwanted pregnancies and reduces the overpopulation crisis. It also prevents problems such as pyometra, cancer and phantom pregnancy.


Things to lookout for

Can a dog in heat get too swollen?

Each dog’s vulva swells differently during their season, but if your dog is painful, uncomfortable, there is a concern about the discharge or her vulva seems out of place and bulping (protruding), talk to a vet.

  • Vaginal prolapse is a result of an exaggerated response of the vaginal mucosa to hormones. The disorder is most commonly seen in young bitches.

How much does a dog bleed when in heat?

Some dogs may bleed heavily, while for others it may be barely noticeable.

It might be harder to notice large quantities of blood if they groom and clean themselves frequently.

How long do they normally bleed for?

It depends on each dog, but usually they bleed from 5 to 9 days and can last up to 20 days in some bitches.


What to do

How to prevent bleeding in the house

To keep your house clean, you may want to:

  • Limit your dog’s access to carpeted areas, sofas and bedding.
  • Use absorbent pads in places where your dog likes to lie down.
  • Use a dog nappy or doggy pants to catch the blood. It’s important to remove the nappy and allow fresh air for part of the day. Change the nappy at least 3 times a day.

How to prevent pregnancy when a dog is in heat

  • Keep your female dog on the lead.
  • Walk at quiet times if necessary to avoid male dog interactions.
  • Avoid leaving her alone in your garden in case a male dog manages to enter.
  • If you have an unneutered male dog, you may need to consider castrating him or moving him to a different part of the house or a different house.

What should you do if your female dog has been mismated or accidentally mates with a male dog?

Contact your vet as soon as possible.

You may decide to go through with the pregnancy. Or you may need to consider ending the pregnancy.

Pregnancy termination

Can be achieved with medications or surgery (spaying).

It is helpful to know the breeding date, as different medications work only during certain stages of pregnancy.

Talk to a vet to discuss what is the best option for your dog since medications can have side effects and may not be 100% effective.


What not to do

Should you let your dog have a heat before getting her spayed?

No, most dogs do not need to have a heat cycle before they are spayed.

Vets usually recommend spaying before the first heat cycle to reduce the chance of mammary cancer.

If your dog is a small breed 6 months of age is the usual age recommended.

However, for large and giant breeds the recommendation may be different. You should always consult a vet before making any decisions.

See our spay article for general advice.

Can a dog be spayed while in heat?

Ideally not.

Spaying a dog in heat increases the risk of excessive bleeding because the blood vessels become much bigger. In addition, hormonal problems such as a long-lasting false pregnancy can develop.

Therefore, you should spay your dog 2-3 months after her season, unless there is a specific reason and your vet advises doing it sooner.

Is there a birth control pill for dogs?

This is not typically recommended due to the very high risks and side effects.


When is it normal

Do dogs go through menopause?

Dogs do not experience menopause due to their reproductive cycles being different from humans.

They can continue to go into heat and become pregnant throughout their lives, even into their senior years, although it may not be medically recommended.

During senior age, it’s normal that your dog’s cycle changes, appearing less often.

Dogs that have stopped having cycles altogether should be examined by a vet, as this can signal an underlying health condition.


When to worry

When should you be worried about your dog in heat?

Take your dog to the nearest vet practice if you see:

  • Greenish/whitish vaginal discharge
  • Smelly vaginal discharge
  • Lethargy
  • Vomiting
  • Something protruding from their vulva
  • Signs of pain

Joii can help if:

  • Your dog is not eating as usual
  • You need help taking care of a dog when she’s in heat
  • Your dog no longer appears to have a season
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