What Is The Best Age To Breed A Female Dog?

Medically Reviewed

At what age do female dogs become ready for mating? And is there an "optimal" age for breeding? This article focuses on these questions, as well as other related aspects to breeding your dog.

best age to breed female dog

Are you wondering whether you should or shouldn’t breed your dog?

And if you do – what age is appropriate?

Whatever you decide in the end, it’s important to be familiar with the basic facts when it comes to dog breeding. Appropriate age is one of these facts.

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If you have a female dog you have an important decision to make – if you should breed your dog or not. This is a rather complex issue and there are a lot of things to consider before you decide. So today, we’re focusing on the female dog and her maturity when it comes to breeding.

So, first of all, let’s explain a couple of things regarding the dog’s oestrous cycle and her maturity process.

When Do Female Dogs Reach Sexual Maturity?

In general, female dogs reach puberty or sexual maturity around the age of six months. However, this can vary a lot, depending on the breed and dog. Some dogs, usually the smaller breeds, can have their first heat cycle as early as four months of age. On the other hand, large and giant breeds can take up to two years before they reach sexual maturity.

It’s important to distinguish sexual maturity from physical maturity. Sexual maturity comes before physical maturity and shouldn’t be taken as a sign that the dog is ready for breeding. But more about that later!

How Often Do Female Dogs Come Into Heat?

This usually happens twice a year, but it can also vary a lot from dog to dog. For some females, three or four heat cycles in a year can be completely normal. In addition, initially the cycles can be very irregular, with time between each cycle different every time. It can take some female dogs up to two years until their cycle becomes regular.

In general, smaller breeds cycle more regularly than what larger breeds do. Some small breeds cycle three or four times per year, while the largest breeds (Great Danes, St Bernard’s etc.) usually cycle every twelve months. Some dogs can even go up to 18 months between the cycles.

What Signs Indicate An Oestrous Cycle?

The most visible sign of your female dog being in heat is vaginal bleeding. The amount of bloody discharge varies between dogs, with some shedding a tiny amount, while others have heavy bleeding. However, it can take a couple of days before this becomes noticeable. Vulvar swelling is therefore the first sign that the heat cycle has begun, alongside the increased attention to her rear end – usually manifested through licking herself.

From the beginning of the cycle, the females will be attractive to male dogs, but they won’t be interested or allow mating until 7-10 days later. As the cycles approaches its end, they bleed less and become more receptive to male dogs.

Another possible sign is small quantities of urine passed more frequently. As the the urine contains both pheromones and hormones, it can be a sign to interested males that the female will be receptive soon. Pheromones are unique chemicals which are secreted by animals, to allow them to communicate with each other.

How Long Does An Oestrous Cycle Last? (Stages of The “Heat” Cycle)

The cycle usually lasts two to three weeks, but this too can vary. Noticing the signs we just mentioned above will indicate the start of the cycle. The cycle is over when the bloody discharge ceases and the vulva returns to its normal size.

The perfect mating time depends on the stage of your female dog’s “heat” cycle, that’s why it’s important to know the cycle phases your dog is going through.

The stages of the oestrous cycle can roughly be presented the following way:

  • 1. Proestrus – This phase usually lasts from 8 to 10 days in healthy female dogs. The vulva begins to swell and the dog starts producing a bloody discharge. The amount of discharge is different for every dog. Female dogs show no interest in males, rejecting any advances and may even be aggressive towards them. /li>

  • 2. Estrus – This stage also usually lasts from 8 to 10 days. The vulva becomes less swollen and the color of the vaginal discharge lightens, varying between clear, pink or slightly brown. The eggs are released from the ovaries, a process known as ovulation, and the female dog becomes ready to accept a male.
  • 3. Diestrus – In this stage the female dog rejects the male dog’s advances and the bloody discharge stops. This phase lasts between 60- 90 days, or around 63 days if the dog is pregnant. False pregnancy can also occur occasionally during diestrus, characterized by the dog increasing in weight, having mammary gland development and showing mothering instincts- even though it is not pregnant! In this phase the hormone progesterone controls the reproductive tract whether or not the female dog is pregnant.
  • 4. Anestrus – This phase lasts between three and four months, and is a transition phase between cycles where no sexual activity occurs. The uterus is being “repaired” after the previous active phases.

The Estrus phase is when your dog is fertile and when you should breed her.

How Do You Know When To Mate Your Dog?

This can be rather tricky, as ovulation can occur both early and late during the cycle. In general, most females will be receptive around the eleventh day, when the discharge isn’t as bloody and the female is looking for a mate and receptive to male dogs.

There are two tests that your vet can perform, it you want to determine when the best time to mate your dog is.

  • Vaginal smear test. A simple examination of vaginal cells, in order to detect changes in cell appearance and numbers. It’s not an invasive test and it’s pretty reliable when it comes to predicting ovulation.
  • Serum progesterone test. This test measures the progesterone levels in the blood. It has become very popular because of its accuracy in predicting successful times for matings, especially for females with a history of unsuccessful mating.

Signs That It’s Time To Breed

If you notice any of the following signs, your female dog is most likely ready to be bred:

  • General flirty behavior
  • Pushing up rear end when you pet her on the back
  • Tail held high and flagging
  • Color change in vaginal discharge, from red to pinkish, clear or brown
  • Frequently presenting her vulva

Having presented all these facts, let’s get to the question that brought you here:

When Can You Breed A Female Dog?

A female dog shouldn’t be bred before she goes through her second or third cycle. As explained, the time between the cycles can be very different from dog to dog. However, it’s very rare that she goes though her third cycle before she’s one year old.

As a rule, females shouldn’t be bred before that.

When it comes to male dogs, they begin producing sperm when they’re approximately 6 months old, but they’re not sexually mature until somewhere between 12 and 15 months of age.

What Is The Best Breeding Age?

Even though both female and male dogs generally reach puberty at the age of 6 months, it doesn’t mean they’re mature or ready for breeding. In other words, just because she can doesn’t mean she should. It’s very important for the female dog to be fully matured before breeding, as early breeding can lead to physical problems, behavioural problems or increased risks for the mum and pups during pregnancy. Give your dog a chance to “grow up”.

Another reason why you should wait until your dog is fully mature is so that you know what genetic predispositions or inherited disorders your dog carries. A common example of a potential health problem is hip dysplasia, which sometimes doesn’t become apparent until the dog is completely mature but may be passed onto the dog’s offspring.

When you’re breeding your dog you want to improve the chances of the puppies being healthy as much as you can, right? And this is impossible to do before a certain age, as you can’t complete some of the basic breeding related health screenings until the dog is physically mature, which is usually around 24 months.

Some dog breeds have an increased risk of passing specific diseases and congenital problems onto their puppies. The Canine Health Information Center (CHIC) has established recommended protocols for breed specific health screenings. The health screen could include a physical examination, x-rays, a DNA mouth swab or blood tests in order to check for certain diseases and conditions. These screenings may also include checking for sexually transmitted diseases which may be passed during mating. Simply put – screenings check for problems that might affect other dogs if the mating were to happen. This is why an ordinary vet check isn’t enough when you want to determine if your dog is healthy for breeding.

To sum it up – it’s difficult to determine an “optimal” age for breeding, but it’s vital that the dog is completely mature before it occurs. Of course, they shouldn’t be “too mature” either. Female dogs shouldn’t be bred when they’re older, as the breeding and whelping process can be very tiring and take a physical toll on older dogs.

How Many Times Can You Breed a Female Dog?

So far, we have understood that a female dog shouldn’t mate before her third heat cycle or after around 6 years old. But how often can you breed your dog? It is known that a female dog, depending on her breed, can have on average two pregnancies each year. But having consecutive pregnancies can harm your dog’s overall health and can potentially cause some health problems.

That’s why it is important to know how to balance the breeding with your dog’s health. Usually, leaving at least a year and a half between each pregnancy will be enough for your dog to recover and have another successful pregnancy.

Is Breeding Safe and Healthy For Your Female Dog?

A lot of female dog owners have doubts if they should breed or spay their dogs. If you’re a professional breeder, you might not want to enter deeply into this question, but the truth is that every dog owner should be aware of the advantages and disadvantages breeding might bring.

Spaying your dog helps prevent some deadly diseases, such as uterine cancer, ovarian cancer or pyometra (infection of the uterus) and significantly reduces the risk of mammary cancer (if your dog is spayed before it’s third season). However, spaying your dog can make your dog more prone to other health issues such as an increased risk of developing urinary incontinence.

Generally, it is thought that an un-spayed or entire female dog will have more balanced hormone levels, higher energy levels and less chance of developing obesity when compared to a spayed dog. Often after a female dog is spayed her change in hormone levels can cause her to put on weight. However, this can often be easily managed with changes to her diet and exercise.

After a female dog is spayed, the veterinarian will often advise that the dog’s weight is closely monitored and the diet adjusted to a lower calorie one if necessary.

Pregnancy is always a tricky state for a female, so you can never know for certain if it will be safe or not. You should also be prepared and ready to aid your dog during whelping and provide everything that’s needed if something goes wrong, because in the end, giving birth can be a difficult task for some female dogs too.

If your dog is spayed or entire, it is equally important to make sure your dog is healthy in all stages of her lifespan. Regular check-ups at the vets is a must and will allow your dog to live a long and happy life.


If you decide to breed your female dog, it’s important to be aware of all the facts mentioned above. Waiting for your dog to be completely physically and sexually mature is crucial when it comes to breeding your dog, both for health and psychological reasons.

Even though dogs can reach sexual maturity as early as six months of age, their full physical maturity comes some time after. Therefore, it’s recommended to wait until the dog has been through at least three heat cycles before she’s ready for breeding. Even though the cycles vary from dog to dog, they’re usually considered fully ready after the age of two.

Finally, it’s very important to understand that every dog is different and should be treated that way. Some dogs reach maturity earlier than others, so you have to know when your dog is completely mature and act accordingly.

Don’t forget to consult with your vet as well, as he might notice signs of mating maturity or immaturity that you might not pay attention to. Your vet can carry out a full physical examination on your dog and discuss possible pre-breeding health screens to ensure your dog and her future pups will be the healthiest they possibly can be!

This article has been medically reviewed by Dr Margarita Boyd, BVSc MRCVS.

Margarita graduated from the University of Liverpool, earning a Bachelor in Veterinary Science with distinction. She worked in small animal and equine practice for a few years, before choosing to focus solely on companion animals. She has developed a special interest in internal medicine and ophthalmology.

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  • Brian Ward

    I have a female Golden Retriever she will be 2 years old in December.

    She is AKC registered and would like to breed her for one litter.

    Looking for a stud Golden Retriever that is AKC registered as well.

    I live in Hilliard Ohio would prefer someone close if possible to breed.

  • jamie

    my fenale british bull dog is in her second season and she is 14 month old can i breed her by ai thanks .

  • Peggy Crane

    My PARSON is 9 & I had not planned to breed her any longer & been a breeder for over 20 yrs. She is healthy & the end of my lines. I am considering it & she is healthy & fit. She has had 4 litters over time & produced many AKC champions in many venues. Just cautious.