Most bitches have their first heat when they are between 6 and 15 months old, and when a dog comes into heat for the first time depends especially on the breed and the dog's size. Small breeds are often early and may begin as early as around six months of age, while the very large breeds sometimes wait until they are a year and a half or older. There is therefore a broad normal range, and it is rarely cause for concern if your young bitch falls at one end or the other of it.
For you as an owner, this means there is no fixed date to mark on the calendar. Instead, it is about knowing the typical signs, understanding what influences the timing, and knowing how best to support your bitch through the first cycle. We will go through all of this here, so you are prepared for the day it happens.
At what age does a bitch typically have her first heat?
The rule of thumb is that a bitch often has her first heat roughly at the same time she approaches sexual maturity, that is, in the transition from puppy to young dog. For many bitches this falls somewhere between half a year and a full year, but realistically the range extends from around 6 months up to a year and a half. Some very large and late-maturing breeds may be even older before the first cycle appears.
Size is the single most important factor. A small bitch of a few kilos usually reaches sexual maturity faster than a heavy dog of a large breed, precisely because the large dogs take longer to finish growing. That is why it is perfectly normal for the neighbour's small terrier bitch to have had her first heat long before your own young Great Dane. Heredity also plays a role, and a bitch will often follow a pattern similar to that of her mother and sisters.
How to recognise the signs of the first heat
The first heat can be discreet, and especially in small bitches it can be so mild that it is easy to miss. The classic signs are a swollen vulva and a bloody or reddish discharge, which is often heaviest at the beginning and becomes lighter and more watery towards the middle of the cycle. Many bitches lick themselves more down there and actually keep quite clean, so the spots on the floor are not always obvious.
The behaviour also changes in some bitches. Some become more affectionate or, conversely, more restless, urinate more frequently to mark, and suddenly become very interesting to male dogs on walks. A well-known sign is what is known as flagging, where the bitch moves her tail aside when touched at the rear. Take note of these signals, because the very first time you don't know when it will start, so it's nice to have caught it early.
The phases of heat and how long it lasts
A full heat typically lasts about three weeks, but it varies from bitch to bitch. It is roughly divided into an initial phase with swelling and bleeding, a fertile phase midway through where the bitch is receptive to mating and the discharge often becomes lighter, and a declining phase where the signs slowly disappear again. It is especially during the fertile phase that you need to be extra attentive if you do not want mating, because here the bitch actively seeks the company of male dogs.
After the first heat, a new cycle usually comes at intervals of a few months, and in most bitches the rhythm typically settles into a pattern of roughly two heats a year. It is worth noting the date of the first heat, so that over time you get to know your bitch's very own interval. If there is anything about the course that seems unusual, or if you are in doubt about your bitch's health, a vet is always the right one to ask.
How to care for your bitch during the first heat
During the heat itself, the most important task is to keep good control of your bitch when you are out. Keep her on a lead on walks, avoid dog parks and places with many loose male dogs, and be aware that a bitch in heat can attract males over surprisingly large distances. Many choose to put the wildest play and dog meetings on hold during the most intense days and instead provide peace and short, calm walks.
Wellbeing also matters indoors. Some bitches are a little more sensitive or tired during the period, and here a fixed routine and gentle handling help. If you want to spare both dog and floors, a soft surface and fixed resting places can make everyday life easier. Above all, remember that the first heat is a completely natural part of having a young bitch, and that the vast majority get through it without problems.
What does food mean for a young bitch that is growing?
The first heat for many bitches falls while they are still in the transition from puppy to young adult. In that phase, a well-considered meal that matches the dog's life stage helps provide a stable foundation while the body grows and matures. At ESSENTIAL FOODS, all meals are premium and made from fresh produce and human-grade ingredients, so you don't have to choose between quality levels, but between nutritional profiles, taste and needs that suit your particular dog.
If your bitch is still rounding off the last puppy months, the BEGINNING series is created for the finest start with luxurious, grain-free puppy meals, fresh produce and carefully selected local and regional delicacies, completely without grain and unnecessary fillers. You can find the prepared puppy meals gathered in the Beginning - kibble, and if your young bitch wants to taste her way forward, the Beginning sample offers an easy way to try the cooked meals. If you want to dive deeper into everything about the young dog, puppy gathers a well-considered universe where the advice comes directly from ESSENTIAL FOODS.
If you are in doubt about what best suits your bitch right now, ESSENTIAL FOODS' nutrition advisers are ready by phone, chat or email to help you find the right meal for the dog's life stage. They advise on feeding, food and nutrition, while you should always raise any health concerns with your vet. With the right preparation, your bitch's first heat becomes a manageable milestone that you both get through well.