What Are the Signs My Dog Is in Heat?

The first signs your dog is going into heat are physical, and they arrive in a fairly predictable order. The vulva swells and becomes firm. A blood-tinged discharge follows a day or two later. She licks at herself more, urinates more often and in smaller amounts, and male dogs within a surprising radius start loitering near your gate. Behavioural change usually comes after the physical change, not before it. This article covers how to read each stage, when in the cycle she can actually conceive, what to do at home for four weeks, and the handful of signs that mean a season has turned into a medical problem.

There is one misconception to clear up straight away, because it causes more unplanned litters than anything else. Owners assume the bleeding days are the dangerous days. They are not. A bitch is usually least willing to mate while she is bleeding heavily, and most fertile about a week after that, once the discharge has faded from red towards straw or pink. Mismatings almost always happen in the second or third week of a season, at the point where the mess has settled and the household has relaxed.

What to Know Vulval swelling usually appears before any bleeding, which makes swelling the earliest reliable sign. A season produces visible signs for roughly two to three weeks, and most bitches cycle about every six months, with five to eight months being normal. The fertile days fall late, typically once the discharge has lightened from red to straw. Keep her on a lead for four weeks from the first sign of swelling. Bleeding that continues past three weeks, or any thick, cloudy or foul-smelling discharge in the two months following a season, needs veterinary attention the same day. Pyometra is life-threatening, and it presents after a season rather than during it.

What Are the First Signs, and in What Order Do They Appear?

Swelling comes first. In most bitches the vulva becomes noticeably enlarged and firm one to three days before any blood appears, and owners who know what they are looking for can predict a season from this alone. The change is easiest to spot in short-coated dogs and easy to miss entirely in a heavily feathered Spitz or a long-coated Indie.

Discharge follows. Early proestrus discharge is frankly bloody, bright to dark red, and the volume varies enormously between individuals. Some bitches leave visible marks on the floor. Others are so fastidious about cleaning themselves that the only clue is the licking. A small Pomeranian may produce almost nothing visible, while a Labrador can need bedding changed daily for a week.

The secondary signs cluster around these two:

• Increased licking of the vulval area, often the very first thing an owner notices in a meticulous dog.
• More frequent urination, in small amounts, usually in more places than usual. She is scent-marking, not developing a bladder problem.
• Male attention from a distance. Intact dogs can detect a bitch in proestrus from well beyond your compound wall. Sudden, persistent interest from street dogs outside the gate is a reliable external sign.
• Tail carriage and flagging. Later in the season she may hold the tail to one side when touched near the base. This is a strong indicator that she has moved into the fertile phase.
• Behavioural change, which varies more than any other sign. Some bitches become clingy and want constant contact. Others become restless, pace at night, go off their food for a few days, or try to escape. A normally obedient dog may ignore a recall for the first time in her life.
• Mounting and humping, of cushions, of other dogs, sometimes of people. It is hormonal, not dominance, and it passes.

What you should not see is systemic illness. A bitch in a normal season is bright, eating reasonably, and behaving like herself with the volume turned up or down a little. Vomiting, obvious pain, a distended abdomen, pale gums or genuine lethargy do not belong to a season and need assessing on the day.

What Are the Four Stages of the Cycle?

The canine cycle has four named stages, and knowing which one she is in tells you what to expect next. Most of the confusion in this subject comes from using "in heat" loosely to mean the whole visible three weeks, when the true heat, oestrus, is only part of it.

Two features of this table matter clinically. The first is that the softening of the vulva, which looks like the season ending, actually marks the beginning of the fertile phase. The second is that dioestrus looks the same hormonally in a pregnant and a non-pregnant bitch, which is why some dogs develop a false pregnancy with mammary enlargement, nesting and milk production six to eight weeks after a season, and why pyometra also appears in this window.

Ranges in this table are wide for a reason. A bitch who runs a short proestrus and a long oestrus will be fertile far earlier than the textbook average, and a bitch with the opposite pattern will be fertile when her owner assumes she is finished. Averages describe populations. They do not schedule individual dogs.

How Old Is a Dog When She First Comes Into Season?

Somewhere between six and eighteen months for most bitches, with size being the main determinant. Small dogs mature early, large dogs late, and giant breeds later still.

First seasons are often atypical, and this catches owners out. A first season may be short, light, or nearly invisible. It may stop and restart a fortnight later, which is called a split heat and is common in young bitches as the ovary fails to complete the first attempt. A split heat is not a fault and usually settles by the second or third cycle. What it does mean is that a bitch who appears to have finished may become fertile again within weeks, so the four-week precaution should be reset from the start of the second episode.

A silent heat is the opposite problem. The hormonal cycle runs normally but the external signs are so mild that nobody notices. The owner reports no season by eighteen months, when in fact two have passed unobserved. Silent heats are more common in first cycles and in fastidious, long-coated dogs.

If a bitch has had no observed season by twenty-four months, book an examination rather than waiting another six. The differentials include silent heats that simply need confirming with hormone testing, an intersex condition, hypothyroidism, poor body condition from parasitism or inadequate diet, and in rare cases ovarian agenesis. Most of these are identifiable with a physical examination, bloodwork and an ultrasound scan, and several are treatable.

How Long Does a Season Last, and How Often Will It Happen?

Visible signs last around two to three weeks. Bleeding is heaviest in the first seven to ten days and tapers after that, and swelling takes a few days longer than the discharge to settle. By week four most bitches look and behave entirely normally.

Interval between seasons is the figure owners most often get wrong, because the commonly quoted "twice a year" is an average rather than a rule. Five to eight months is a normal range, so some bitches genuinely cycle three times in two years and others only once a year without anything being wrong. German Shepherds tend towards shorter intervals of four to five months. Basenjis typically cycle once annually. Free-roaming dogs in Indian cities are reported to show some seasonal clustering, with cycles concentrated in the cooler months and a corresponding peak of puppies afterwards, though owned dogs living indoors under artificial light show little of this pattern.

Consistency matters more than the number. A bitch who has reliably cycled every seven months and then goes eleven months without a season has changed, and that change is worth investigating. The same applies in reverse. Intervals shortening to under four months, or bleeding appearing between seasons, suggests an ovarian cyst or a follicle that failed to resolve, and both are diagnosable on ultrasound.

Bitches do not go through menopause. Cycles become less regular and less fertile with age, and the interval often lengthens, but an unspayed bitch of twelve may still come into season. This is clinically relevant because the risk of pyometra rises with each cycle and with age. An elderly bitch having a season is not a reassuring sign of youth. She is an animal whose uterus has now been exposed to progesterone many dozens of times.

When Is She Actually Fertile, and How Can I Tell?

Fertility sits late in the visible season. The chart below maps the signs against the days, counted from the first day of bleeding.

The practical implication is uncomfortable for owners who have been counting down. Precautions need to run for about four weeks from the first sign of swelling, not until the bleeding stops. A bitch who looks clean and calm on day fourteen may be at the exact midpoint of her fertile window.

Three factors widen the window further. Dog sperm can survive in the female reproductive tract for several days, so a mating that happens before ovulation can still produce a pregnancy. Eggs ovulated by the bitch need around two days to mature before they can be fertilised, which pushes the effective window later than the behavioural signs suggest. The duration of standing heat varies between individuals and between cycles in the same individual.

If timing matters, because you are planning a mating or because a mismating has occurred, the only reliable method is laboratory measurement. Progesterone testing on serial blood samples, usually every two to three days through the suspected window, identifies the hormonal rise that precedes ovulation. Vaginal cytology adds supporting information by showing the shift in cell type as oestrogen peaks. Counting days from the first spot of blood and watching for flagging are useful for managing risk at home. They are not accurate enough to plan a breeding.

An unplanned mating is time-sensitive. Contact a vet within twenty-four to forty-eight hours rather than waiting to see whether she looks pregnant, because the available options narrow quickly and the safest ones are the earliest ones. Over-the-counter and traditional remedies for this situation do not work and can cause harm.

How Do I Manage a Dog in Heat at Home?

Assume four weeks of altered routine from the day you notice swelling. Most of the management is simple containment, and most failures are failures of imagination about how determined an intact male can be.

Exercise. Keep her on a lead for every outing, including trips to the gate and short garden breaks if the garden is not fully secure. Off-lead walks, dog parks, beaches and group day care are out for the full four weeks. Scent carries a considerable distance, and free-roaming dogs are a genuine factor in most Bengaluru neighbourhoods, so a bitch in proestrus may draw several males to your street within a day. Walk early or late, when fewer dogs are out, and change your route if a particular stretch has become a problem.

Containment. Check gates, grilles and gaps at ground level before the season starts rather than after. Mating through a gate or a compound wall gap happens often enough that it is worth a slow walk around the boundary. Bitches in oestrus also attempt to escape, including dogs with no previous history of it, so a reliably closed door matters more than usual for a few weeks.

Dogs in the same household. An intact male in the same house cannot be managed by supervision alone. He will not sleep, he may stop eating, he may vocalise for days, and a few seconds of inattention is sufficient. Either he moves out for the duration or the two of them are kept in genuinely separate rooms with a solid closed door between them. Related dogs still mate. Dogs who have grown up together still mate. Castration of the male solves this permanently if neither is intended for breeding, though it takes several weeks after surgery to be reliable.

Hygiene. Washable bedding and a confined sleeping area deal with most of the mess. Dog nappies or season pants work for some dogs and are useful for indoor flats, but they need changing frequently, because a damp nappy against swollen tissue encourages infection. Do not use them continuously overnight without checking. Let her lick, within reason, since self-grooming is normal. Excessive washing of the vulval area is unnecessary and can cause irritation, and douching or inserting anything into the vagina should not be attempted at home.

Behaviour. Expect some regression in training and do not treat it as disobedience. Appetite may dip for a few days. Sleep may be broken. Keep sessions short, be patient, and resume normal expectations once the season has finished.

Could the Signs Be Something Other Than a Season?

Often, yes, particularly if the picture is not quite typical. Blood at the vulva is not specific to oestrus, and several of the alternatives are serious.

Two of these deserve expanding, because both are relevant in this region.

Transmissible venereal tumour is a sexually transmitted cancer passed between dogs at mating. It is common wherever free-roaming dog populations are large, which includes much of urban India, and it typically presents as a friable, cauliflower-like mass protruding from the vulva or prepuce that bleeds easily. Owners frequently mistake the bleeding for an unusually long season. It responds well to chemotherapy when treated, and the prognosis is genuinely good, so a mass at the vulva should be examined rather than watched.

Tick-borne disease matters because Bengaluru has a substantial tick burden year-round and a worse one after the monsoon. Ehrlichia and related organisms can lower platelet counts enough to cause spontaneous bleeding, and a bitch bleeding from the vulva with no swelling, or bleeding alongside bruising on the belly, pinpoint spots on the gums, or lethargy, may be bleeding for haematological reasons rather than reproductive ones. This is an emergency and a blood count usually answers it within the hour.

Vaginal hyperplasia is the third thing worth recognising. Under oestrogen influence, vaginal tissue in some bitches swells and protrudes through the vulva as a smooth pink or red mass. It is more common in brachycephalic and large breeds, it is not cancer, and it usually regresses as hormone levels fall. Exposed tissue dries, ulcerates and can obstruct urination, so it needs assessing and sometimes protecting while it resolves.

When Does a Season Need Veterinary Attention?

A normal season needs no medical input. The list below is the set of situations where it does.

Pyometra is the reason this section exists. It is a pus-filled infection of the uterus that develops under the progesterone influence of dioestrus, which means it appears in the weeks after a season rather than during it, usually two to eight weeks later. The risk accumulates with every cycle a bitch goes through, and middle-aged and older unspayed bitches are the typical patients. Where the cervix stays open, pus drains and the owner sees a foul discharge. Where it closes, nothing drains, the uterus fills, and the only signs are systemic: drinking more, off food, vomiting, lethargy, a tender abdomen. Closed pyometra is the more dangerous presentation precisely because it looks like a vague illness.

Treatment is usually surgical removal of the uterus and ovaries, performed as an emergency on a patient who is often dehydrated and may be in early kidney compromise. Outcomes are good when dogs are presented early and considerably worse when they are presented after several days of deterioration. If an unspayed bitch becomes unwell within two months of a season, say so when you book. That single piece of history changes the order in which a vet investigates.

False pregnancy belongs in the same part of the calendar and is frequently confused with pyometra by worried owners. Six to eight weeks after a season, some bitches develop mammary enlargement, milk production, nesting behaviour, reduced appetite and intense attachment to toys or other objects. The cause is the fall in progesterone at the end of dioestrus and the rise in prolactin that follows it. This is a normal hormonal event rather than an illness, and it resolves on its own over two to three weeks in most cases. A bitch who has done it once will usually do it after every season.

See a vet if the mammary glands become hot, hard or painful, if she is systemically unwell, or if the behaviour is severe enough to distress her. Do not restrict water, and do not milk the glands, since stripping them stimulates further production. Removing the adopted toys helps some dogs and upsets others, so judge it by her response. Medication is available for persistent or uncomfortable cases and works well. Repeated false pregnancies are one of the reasonable arguments for spaying, and the surgery is done once the episode has fully settled rather than in the middle of it.

Does Spaying Change the Picture, and When Should It Be Done?

Spaying removes the cycle, which removes seasons, unplanned pregnancies, pyometra and false pregnancies. The procedure removes the ovaries, with or without the uterus, and a correctly spayed bitch does not come into season again.

Timing is the part that genuinely divides opinion, and anyone who tells you there is one correct age for every dog is oversimplifying. Spaying before the first season gives the greatest reduction in mammary tumour risk, and the protective effect decreases with each subsequent cycle. Against that sits evidence in some large and giant breeds that removing sex hormones before growth plates close is associated with a higher rate of certain joint problems and, in a few breeds, specific cancers. Urinary incontinence is a recognised complication, more common in larger bitches and in those spayed very young. Weight gain after spaying is real, predictable and manageable with a modest reduction in food.

The practical position is that a small or medium-sized bitch with no breeding intention is usually best spayed before her first season or shortly after it, while a large or giant breed warrants a conversation about waiting until she is skeletally mature. Temperament, household circumstances, whether there is an intact male nearby, and how well a season can realistically be managed all legitimately affect the decision.

Two pieces of practical timing. Do not spay during a season. The reproductive tract is heavily vascular at that point, which increases surgical bleeding without benefit, so unless there is an emergency the usual advice is to wait two to three months after the bleeding stops. Equally, do not spay during a false pregnancy, since the sudden hormonal change can prolong the lactation.

Signs of a season in a bitch who has already been spayed are abnormal and should be examined. The usual explanation is a small piece of ovarian tissue left behind or, rarely, a separate ectopic ovary, and the condition is called ovarian remnant syndrome. It is confirmed with hormone testing and treated surgically. The alternative explanations, including a vaginal or urinary tract problem, matter just as much, so the bleeding should not be dismissed as a quirk.

Frequently Asked Questions

Next Steps

If your bitch is unwell within two months of a season, with vomiting, lethargy, a reduced appetite, increased thirst or any thick or foul-smelling discharge, treat it as an emergency and contact us the same day. Pyometra responds well to prompt surgery and poorly to delay. The same applies to bleeding with pale gums or bruising, to tissue protruding from the vulva, and to a mating you did not intend, where the useful window is the first day or two.

If the picture is an ordinary season, there is little to do beyond containment. Keep her on a lead and away from other dogs for four weeks from the first sign of swelling, check your gates and boundaries, keep an intact male in the household behind a closed door rather than under supervision, and keep the bedding washable. Note the date the bleeding started, because that single number makes every future conversation about her cycle more useful.

If you are weighing up spaying, or you are unsure whether what you are seeing is a season at all, book an examination with our team. We can confirm the stage of the cycle, run progesterone testing where timing matters, rule out the conditions that mimic a season, and talk through the right age to spay for your dog's breed and size rather than for dogs in general.