Most bitches are in heat roughly twice a year, that is, at intervals of about six months. That is the typical answer to the question of how often dogs come into heat, but it covers a wider variation than many people expect. Some bitches have a heat every eight months, others only once a year, and in certain breeds you see a very fixed pattern that differs from the average. The interval depends, among other things, on breed, size, age and the individual dog. Below we go through what is normal, when the pattern typically settles, and how you can best support your bitch through the period.

How often are dogs in heat per year?

The rule of thumb is two heat cycles a year with an interval of about six months. This applies to the majority of bitches, but it is worth emphasising that "normal" here is a range and not a fixed number. Counting backwards from two heats a year means that there is typically half a year between your dog coming out of one heat and going into the next. Some bitches have slightly more frequent heats with about four to five months in between, while others have longer breaks of up to eight to twelve months. As long as your dog's own pattern is reasonably predictable and repeats itself with the same spacing each time, this is in principle a completely normal rhythm for her.

What matters, therefore, is not whether your dog hits exactly twice a year, but whether her cycle is regular for her. If you keep a little calendar of when the heats begin, you quickly get a picture of her personal interval. That is the knowledge that enables you to plan and to recognise if something later changes.

What do breed and size mean for the interval?

Breed and size have a noticeable influence on how often a bitch is in heat. Smaller breeds often come into their first heat earlier and can have a slightly more frequent cycle than large breeds. In several large and giant breeds, on the other hand, you often see only one heat a year, which is completely natural for them. A few breeds are known for a fixed, deviating pattern, where there is, for example, only a heat every eight to twelve months, without this being a sign that anything is wrong.

That is why it makes the most sense to measure your dog's interval against what is typical for her particular breed and size, rather than against a general average. If you know your breed's normal pattern, it also becomes easier to assess whether your bitch's rhythm is where it should be. If you have a large dog, you can read more about what they need in everyday life in our guide on Large Dog Breeds Choices And Meals.

When does the first heat arrive, and when does the pattern settle?

The first heat occurs for most bitches somewhere between six months and a year and a half, and small breeds are often earlier than large ones. It is important to know that the first heat does not always give the final picture of how often your dog will be in heat from then on. In young bitches in particular, the first couple of cycles can be a little irregular, both in spacing and in how they proceed. This is completely common, and the pattern usually settles as the dog gets older.

So expect that it is only after the first two to three heats that you can really read your dog's fixed rhythm. That is precisely why it is a good idea to note down the dates from the start. Then you have a solid basis for comparison when you later need to assess whether the interval is stable.

Does the heat change as the dog gets older?

Yes, the rhythm can change over the course of life. Dogs do not go through menopause in the same way as humans, and a healthy bitch therefore continues to have heats throughout her life, unless she is spayed. But in the older bitch the intervals often become longer, and the heats can become weaker and more irregular than they were in the younger years. This is a natural part of moving into the senior years and is usually not something that in itself gives cause for concern.

What is worth being aware of is major and sudden changes in the pattern. If the heats come much closer together, much further apart, or if you see changes in discharge or behaviour that you do not recognise, it is wise to have it assessed by a vet. This applies, moreover, throughout life: if you are in doubt about anything health-related regarding your dog's cycle, the vet is the right person to examine it. If you want to read more about what you can do to make the senior years good, we have gathered advice in How Your Dog Thrives Best.

How long does a heat last, and how does it proceed?

The heat itself typically lasts about three weeks, and it proceeds in phases. In the first part the bitch begins to bleed, and male dogs are attracted, while she is not yet willing to mate. In the following phase the discharge often changes character, and this is when she is receptive to mating. After that the signs gradually subside, and the dog falls back into her calm resting phase until the next heat approaches half a year later. Precisely because the heat itself lasts a few weeks, while the break in between lasts months, it can be useful to keep the two things separate when you work out how often your dog is in heat. If you want to dive deeper into the duration, you can read more in our article How Long Is A Dog In Heat, and if the bleeding is a concern for you, we go into detail on it in How Long Does A Dog Bleed In Heat.

Knowing the phases makes it easier to understand your dog's behaviour and to plan everyday life, for example when extra supervision on the walk is a good idea. At the same time it makes it easier to recognise when a new heat is on the way, so that the interval between them becomes more tangible.

How to support your dog through the heat

The heat is a period when many bitches change behaviour. Some become more clingy or searching, others a little restless or less interested in food for a few days. The best thing you can do is give her calm, predictability and a little extra closeness, as well as keeping a close eye on the walks, where interested male dogs may show up. If your bitch has less appetite for a few days, this is often temporary, but if it persists, or if she seems off, you should contact your vet.

A stable everyday life also rests on good, nourishing meals all year round, regardless of where your dog is in her cycle. At ESSENTIAL FOODS all our dog meals are prepared from fresh produce and human-grade ingredients, so that your bitch gets a firm, tasty anchor point in everyday life. If you are in doubt about what suits her particular life stage, size and needs, our nutrition advisers are ready by phone, chat and email to help you put together the right meals. If you want to see the whole selection, you will find it under Dog Meals, and if you have a smaller dog, you can find inspiration in For Small Dogs.

Whether your dog is in heat twice a year or follows her very own rhythm, the most important thing is that you know her normal pattern and react if it changes markedly. With a little note-taking, attention and a secure everyday life around her, you are well equipped to follow her through every single cycle, and to know when it is time to ask the vet for advice.