When we welcome a young dog, we are often a little surprised by her first heat!

But don’t worry: the “dog’s period blood” can be managed without difficulty provided you take the right precautions for the comfort of the animal.

Here’s everything you need to know about this subject.

At what age do female dogs get their first period?

Can we really say that female dogs have period blood?

We wrongly say that the female dog has her period.

In fact, the bloody vaginal discharge in the female dog is a way of attracting males to reproduce.

This is the only time when the female dog is fertile, unlike the woman, in whom having period blood means that the egg has not been fertilized.

Also, menstrual blood in women is not ultimately blood. Indeed, it is partly blood and partly fragments of uterine tissue due to the sloughing of the uterine lining.

Whereas, in female dogs, it is actual blood that comes directly from the vaginal walls. This phenomenon is called diapedesis, in which, red blood cells pass through the membranes of the uterus.

Puberty in dogs or the apparition of the first heat

Puberty in female dogs appears between 6 and 24 months of age, with an average of 12 months.
The size of the female dog is the crucial factor determining the age of puberty:

  • 5 to 6 months for small breeds.
  • 6 to 8 months for medium breeds.
  • 12 to 15 for large breeds.
  • 18 to 24 for giant races and molossoids

At puberty, the growth of the female dog is not complete yet and her fertility is limited. Which means that she is not ready to undergo pregnancy.

The estrous cycle in female dogs

The estrous cycle in dogs is the set of structural and functional modifications of the female genital system, and also the behavioral ones which occur from one estrus to another.

There are mainly, 4 phases in the estrous cycle:

  • Proestrus (the beginning of the sexual season)
  • Estrus (the phase of male receptivity A.K.A. “the mating phase” = Proper heat phase)
  • Metestrus/diestrus (the phase of male rejection, it comes after ovulation and ends with a pregnancy if the ovule has been fertilized. Sometimes, pseudopregnancy can occur during this phase)
  • Anestrus (The interval between two episodes of heat, also called inter-estrus = sexual rest phase)

In the following table you will find the details of each phase of the estrous cycle in female dogs:

ProestrusEstrusMetestrus / DiestrusAnestrus
Lasts 7-15 days with an average of 9 days.Lasts 7-21 days with an average of 9 days.50 to 70 days.Lasts 2 to 9 months with an average of 5 months.
Male Attraction but no receptivity.Male Attraction with receptivity.No attraction or interest in males and no receptivity.Rest phase in preparation for next estrus.
– Swelling of the vulva;
– Bleeding (bright red discharge);
– Tail tucking (or sitting when a male approaches);
– Change in appetite (either decrease or increase);
– Behavioral change (either affection or aggressivity).
– The vulva is soft and less swollen (to facilitate penetration)
– Bleeding (pink discharge)
– The tail is moved to the side and the back is arched (inviting males to mate)
– Period of life of the corpus luteum.
– It corresponds to the length of a gestation period.
– The vulva gradually regains its pre-heat size.
– Swelling of breast tissue, depending on gestation.
– Possible presence of milk at the end of metestrus.
– High blood level of Progesterone (whether the female is pregnant or not)
– No physical modifications visible externally;
– Uterine involution: 70 to 90 days depending on the occurrence of pregnancy;
– Hormonal changes: basal production of estrogen and progesterone.
Descriptive table of the different stages of the estrous cycle in the female dog

How to recognize that your dog is in heat? (heat symptoms)

We say that a female dog is in heat or in the season when we notice the following signs:

  • Swollen pink vulva;
  • Bloody vaginal discharge (Serosanguineous during proestrus then Seromucous during estrus);
  • Approaching and teasing male dogs;
  • Frequent urination (peeing);
  • Frequent licking of the vulva;
  • Attracting male dogs (the effect of pheromones)
  • Mating posture (Arched back with the tail moved to the side);
  • Exhibiting some behavioral changes (excitement, lack of appetite, aggressivity towards people or increased interest and affection, the need to go outside roaming).

How can you manage your dog’s period?

Managing your dog’s period revolves around three major aspects:

1. Avoiding contact with male dogs:

In order to prevent pregnancy and, eventually, venereal diseases you need to watch out for male dogs.

So, it would be preferable to avoid any outside activities with your female dog during the heat period. Including hiking and walking in the park or, at least, no more off-leash time during outside walks.

2. Handling the vaginal discharge (bleeding):

This is by far the most annoying part of a dog period especially if you live in an apartment with your dog.

Your house can get messy rapidly, with blood stains and foul odors all over the place.

Fortunately, there is a practical solution to those problems which consists of using diapers specifically designed for dogs (with a hole for the tail).

There are many brands of dog diapers in the market with a variety of types and sizes:

3. Handling her behavioral changes:

Many dogs don’t get along well with other dogs during their period. Some of them might even growl at their owners.

So, the best thing to do is to give your dog some space in a room separated from other dogs and let her decide the amount of interaction she wants to have with you.

In other words, don’t try to approach her unless she wants you to!

Also, you need to keep your dog entertained at home with toys and interactive games.

What to do during heat if you have a male dog at home?

Physical separation:

As obvious as this might sound, the best thing to do during the heat in the presence of a male dog at home is to separate them:

You need to isolate one of them by putting him indoors while the other one is in your yard.

Ideally, I recommend isolating the female and keeping her away from your yard or any other open space.

Because she might try to escape looking for potential mating partners or even attract stray dogs with the pheromones she releases.

If you live in an apartment, separating your dogs can be quite tricky. Especially, if the male exhibits any aggressive behavior towards the female.

As a solution to this problem, you should consider putting the male in a kennel during the heat period, which lasts around 3 weeks.

Some dogs struggle with sudden changes in the environment. So to help your dog get used to kennels, you may take him to visit the kennel or even have him stay for short periods before the heating phase.

Masking the heat smell:

You can achieve that by applying a dog perfume to the posterior tract of your female dog.

This won’t mask the scent definitively, as the dog’s sense of smell is highly developed. But, it can reduce its strength or even repel the male dog.

Using diapers:

In addition to managing the vaginal discharge and keeping your house clean, diapers can play the role of a physical barrier to mating should your dogs get united in the same place during the heat.

When do female dogs stop going into heat?

The age at which a female dog stops going into heat (estrus cycle) can vary depending on your dog’s breed. Generally, smaller breeds tend to go through menopause later than larger breeds.

On average, female dogs may stop going into heat anywhere between 6 and 12 years of age, but some dogs may continue to go through estrus cycles even into their senior years.

It’s important to consult with a veterinarian to discuss options for spaying or managing the estrus cycle of your female dog.

Do female dogs get periods after spaying?

After spaying, female dogs no longer have periods as the spaying surgery, also called ovariohysterectomy*, consists of the removal of the ovaries and uterus.

  • The ovaries are responsible for the secretion of progesterone and estrogen
  • The uterus is the organ where the fetus is attached and developed

Nevertheless, some female dogs can still exhibit some heat signs even after spaying. Which is caused by a condition called ovarian remnant syndrome.

This syndrome can happen if a small portion of ovarian tissue remains inside the dog’s body after the surgery. Or, if an accessory ovarian tissue developed in the body with enough blood supply to release estrogen in the bloodstream.

* Spaying can also consist of ovariectomy, which is the ablation of ovaries only, but it’s recommended to remove both the ovaries and uterus to prevent some eventual uterine diseases such as tumors.

What you need to remember

Period blood in female dogs is different than a woman’s menstruation

Puberty in female dogs is around 12 months of age on average:

  • Small breeds (can be as early as 4 months)
  • Big breeds( can be as late as 2 years)

A female dog is in heat on average every 6 to 7 months.

Heat lasts an average of 3 weeks.

A period of 2 months of progesterone impregnation is systematic after the heat.


How long do female dogs bleed on their period?

Female dogs can bleed, on average, for 9 to 18 days during their period depending on the breed and size of the dog (some dogs can bleed as few as 7 days while others may bleed for more than 21 days).

How do I stop my female dog from bleeding everywhere?

You can stop your dog from bleeding everywhere simply by using dog diapers.

How can I keep my house clean with my dog in the heat?

You can keep your house clean with a dog in heat by:

  • Using diapers;
  • Reserving a potty pad for your dog;
  • Isolating your dog in a small room:
  • Frequent cleaning your dog’s hind trail.

Do dogs bleed every month?

After puberty, female dogs will bleed every 5 to 6 months on average depending on size and breed during the heat period.

Do dogs get cramps on their periods?

Yes, dogs do get cramps during their period, though they might not be as noticeable as in women.

Do female dog periods smell?

Female dog periods tend to have a foul odor, fortunately, you can attenuate the smells by adopting a good hygienic routine and using some dog perfumes and deodorants.

First heats come with a load of physical behavioral and hormonal changes:

What should I expect when my dog goes into heat for the first time?

  • You should expect bloody vaginal discharges all over the place;
  • Some behavioral changes such as excess aggressivity or tenderness;
  • Escaping attempts looking for male dogs.

Do female dogs bleed the whole time they are in heat?

A female dog in heat will bleed during both proestrus (bright red discharge) and estrus (pink discharge). Which last on average, 9 days each. This means that the bleeding will last around 18 days give or take depending on the breed and size of the dog. (Check this section for more details)

Is it okay for dogs to lick their period blood?

Normally, it is no big deal for your dog to lick her period blood, in fact, it can be beneficial for her as she can get some minerals and nutrients back from the discharges. Yet, what would be problematic is the act of over-licking the vulva, as this behavior can cause some uterine infections.

Photo credits

Featured image:

Mazzie’s Diaper” by Dance Party Duo is licensed under CC BY-NC-SA 2.0.

Pin It on Pinterest

Share This