Heat in Female Dogs: Signs, Duration & Stages 

Why Do Many Dog Owners Dread Their Female Dog’s First Season? 

For many dog owners, the time when their female dog is in season can feel like running the gauntlet. They barricade themselves at home and avoid long walks in the park. In this way, they want to avoid stressful encounters with unneutered males who are seemingly just waiting for their female dog in season.

At the same time, they nervously cover their beds and upholstered furniture with old sheets to prevent unsightly blood stains. After all, furniture is expensive, and most owners can certainly do without an unwanted pregnancy.  

A Female Dog in Season: Tips and Tricks

But relax: with a few handy tips and tricks, you can get through the phase without any problems and won’t need to worry about unwanted puppies. As so often, the better informed you are about the process of coming into season and the changes associated with it, the more relaxed you and your dog will be during this time. 

The Most Common Questions about a Female Dog in Season 

A season (also called heat) refers to the fertile phase of a female dog’s cycle. The hormones shift and her body and behaviour change. This natural process occurs in all female dogs that have reached sexual maturity. 

When Does a Female Dog Have Her First Season? 

As with humans, the onset of puberty and the associated start of sexual maturity can vary greatly in female dogs, too. What matters for the timing of a dog’s first “period” is that she is very variable. The key factor is that the female dog is fully grown and has reached her full size.  

The female dog’s first season usually occurs slightly later in large breeds than in small breeds. Large breeds typically have their first season from around ten months of age. Small breeds, on the other hand, can come into season for the first time from as early as six months. In rare cases, however, dogs may not have their first season until after 18 months of age. 

How Often Does a Female Dog Come into Season? 

How frequently a female dog comes into season also depends on individual factors such as breed. Small dogs generally come into season twice a year. By contrast, large female dog may come into season only once a year.   

How Long Is a Female Dog in Season and How Long Does She Bleed?

This question concerns most owners: How long will my female dog bleed? As a rule of thumb: the bleeding lasts for the duration of the season at most – that is, for around 18 days. Depending on the consistency and amount, the discharge may appear more or less heavy. 

What Behaviour Does a Female Dog in Season Show? 

Among the clearest signs of a female dog being in season are certain behavioural changes. Your dog’s mood can fluctuate greatly during her season. At first, she may still be very dismissive towards males. As the heat progresses, she seeks their company and is ready to mate. Behaviour at home can change too. Some female dogs seem calmer than usual to their owners. Others, meanwhile, become more excitable and less obedient than normal. This is one of the normal side effects of being in season.

Duration: How Long Does a Female Dog’s Season Last? 

The entire season (proestrus + oestrus) lasts around 18 days. 

How Do I Know When the Season is Over?

The end of the season is reached when the vulva swells down and there is no longer any discharge. Your female dog returns to her usual behaviour and is no longer receptive to males keen to mate.

Do Dogs Go Through the Menopause? 

Unlike humans, dogs do not experience the menopause. There is no phase in which menstruation stops in these four-legged friends. A healthy, unneutered female dog will therefore come into season for the rest of her life. However, the interval between seasons may increase as she gets older. 

What Are the Signs of a Female Dog’s Fertile Days? 

The fertile period, during which your female dog is ready to mate, usually lasts five to six days. As the transitions between phases are gradual, it is not always possible to pinpoint the “hot days” precisely. Nevertheless, some indications suggest that your female dog may be ready to mate: 

• the colour of the blood during the season changes from dark red to a lighter, watery discharge 
• when you stroke her back your female dog moves her tail to one side and raises her vulva (standing reflex)

However, these signs do not give you one hundred per cent certainty. Some female dogs will allow mating even when their blood is still dark red. Only your vet can give you reliable information about your female dog’s fertile days. They can determine the time of ovulation. 

How Long is a Female Dog Fertile After Bleeding Starts?

Roughly between the 5th and 13th day of the season a female dog is receptive to mating. The fertile period therefore lasts around five to six days. When the bleeding subsides, the so-called metoestrus (post-oestrus) begins. The female dog is then no longer ready to mate and will give interested males the cold shoulder.

What Is the Reason if a Female Dog Does Not Come into Season? 

If your adult female dog does not come into season, this may be due to various health-related causes. For example, a disorder of ovarian function or other conditions (such as hypothyroidism or overactive adrenal glands) may be responsible.  

In this case, you should have your female dog examined by your vet as a precaution. The same applies if your female dog’s willingness to mate lasts longer than three weeks or if the season is noticeably shortened. If the bleeding during your female dog’s season does not stop or does not start at all, this is always a reason to visit the vet.

Is It Necessary to Use Season Pants? 

Season pants are similar to a dog nappy that you can put on your female dog during her season. They are advisable if your dog bleeds heavily during proestrus and it is impossible to avoid red stains in your home. But take care: these pants are not a chastity belt! A pregnancy cannot be prevented by season pants. 

Tip: Absorbent and waterproof dog blankets will keep your furniture and carpets clean and dry during the season. Faux leather dog beds can also be wiped clean easily, helping you maintain good hygiene.

You’ll find even more choice of dog accessories in the online shop at zooplus.

What Are the Phases of a Female Dog’s Season? 

Although the interval and duration of the season can vary considerably, the heat cycle follows the same pattern in all female dogs. The sexual cycle is therefore divided into four phases: 

1. Proestrus (Pre-Oestrus): Coming into Season

A female dog’s season occurs in several phases. The start of proestrus can usually be identified quite clearly, as it is accompanied by visible changes: your female dog’s vulva swells and releases bloody discharge. 

Physical Signs

The amount of bloody discharge varies from dog to dog. In some female dogs it is barely noticeable, while others bleed heavily. Some owners therefore need to protect their furniture from red stains. 

Behaviour

During pre-oestrus, you may also notice an increased interest from males. They suddenly won’t leave your female dog alone. Even though she is not yet fertile at this stage, she already gives off a very “seductive” scent. However, she still reacts to advances from her male admirers in a snappy and dismissive way. She barks and moves away. Sometimes she even shows her teeth if a male becomes too pushy. 

Duration: around 9 days 

2. Oestrus (Heat): Standing Heat

Oestrus is also known as “standing heat”. During this time, several ovulations occur. If mating takes place during these days, the likelihood of fertilisation is high.

Physical Signs 

The vulva swells down slightly. The vaginal discharge also changes, becoming more watery and sometimes mucous-like.  

Behaviour

During the heat phase (standing phase) of oestrus, your female dog drops her dismissive behaviour. She suddenly responds to males’ advances with interest and openness, as she is now ready to mate and fertile. If a male approaches at this time, she will stand still willingly and move her tail to one side.  

Duration: around 9 days 

3. Metoestrus (Post-Oestrus)

Metoestrus follows the season (proestrus + oestrus). Regardless of whether fertilisation has occurred, the corpus luteum in the ovary produces the hormone progesterone. This promotes implantation and the growth of the embryo in the uterus.

Only after nine to twelve weeks does the body break down the corpus luteum formed after ovulation. The resulting drop in progesterone levels then stimulates the production of the hormone prolactin.

Physical Signs 

The typical signs of being in season (swollen vulva, watery discharge) gradually disappear. You can recognise the end of the season by the disappearance of these external signs. Internally, however, hormones continue to cause various changes in your dog’s body. 

Behaviour

The release of prolactin stimulates milk production in your female dog. In some dogs, this leads to a phantom pregnancy. If your dog is experiencing a phantom pregnancy, she is usually more affectionate and calmer than usual. In addition, her mammary glands swell and she may start nesting, even though she is not actually pregnant. 

Duration: around 90 to 120 days 

4. Anoestrus (Resting Phase)

After many weeks of significant hormonal changes, your female dog’s sex hormones return to their “normal” state. Progesterone remains constant and oestrogen levels fluctuate only slightly. During this time, the female dog shows no signs of being in season and is not fertile.

Duration: around 60 to 90 days 

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Special Features of a Female Dog’s First Season 

A female dog’s first season often does not strictly follow the rules set by nature. The symptoms of the first season may therefore differ from those in later years.

Silent Season 

Does a female dog change during her first season? Not necessarily. Occasionally, the first season is what’s known as a “silent season”. Despite the hormonal changes, you may not notice any external signs. It becomes problematic if you, as the owner, are completely unaware that your female dog is in season for the first time. In the worst-case scenario, your female dog may be mated unintentionally. Breeds such as the American Staffordshire Terrier, Beagle, or Cocker Spaniel are more commonly affected.  

Split Oestrus 

So-called “split oestrus” is also not uncommon in young female dogs. In this case, typical signs of season such as discharge appear during proestrus at first. However, these do not lead into oestrus but instead subside completely again. Only after a few days or weeks does your female dog show signs of pre-oestrus again, followed by oestrus this time. 

Your Female Dog Is in Season? How to Prevent Pregnancy without Neutering 

Even if you cannot pinpoint your female dog’s heat phase to the exact day, there are signs that indicate she is in season. At the latest, when the bleeding becomes more watery and your female dog stands still during advances from male admirers, you should take care.  

As a rule, you still have a small window of time in this situation to separate the two dogs before actual mating occurs. After all, most males do not immediately mount your female dog but begin with some courtship.

Prevent an Unwanted Mating

Here is what you can do in this situation: 

• give your female dog the “sit” or “down” command
• stand behind your female dog in season 
• keep the male dog at a distance and wait until his owner puts him on the lead  

What Can You Do to Make Things Easier for a Female Dog in Season?

To avoid such stressful situations from the outset, you should bear a few points in mind during her season: 

• go for walks at times when there are as few dogs around as possible avoid green spaces  
• where lots of dogs run around (off lead)  
• only let your female dog off the lead during her season if she has reliable recall 
• put her straight back on the lead as soon as you encounter another dog
• try to distract your female dog on walks with more intensive games  
• make sure at home that love-struck males from the neighbourhood cannot simply enter your property
• keep your front door and garden gate securely closed 

What Are the Pros and Cons of Neutering a Female Dog ? 

To avoid the stress of a season, many owners opt for neutering. Unlike sterilisation (where the female dog cannot have puppies but still undergoes hormonal changes), neutering prevents seasons altogether.

There are certainly advantages to this major medical procedure. Neutered female dogs are usually calmer and no longer bleed. Studies also show that neutering reduces the risk of certain cancers (e.g. mammary cancer) significantly.

Anaesthesia as a Risk Factor

However, there is another side to the coin. Neutered female dogs often suffer from being overweight, and the risk of urinary incontinence increases with age. In breeds such as the Cocker Spaniel and Irish Setter, a change in coat texture has also been observed after neutering. In addition, there are the risks associated with surgery itself, such as bleeding or infections. The anaesthetic also poses a certain health risk for your female dog.

Before deciding to have your female dog neutered, you should weigh up the pros and cons carefully. You should also seek advice from your breeder or vet when making your decision.

Conclusion: How Long Do You Need to Be Cautious During a Season?

Your female dog is in season – how long should you take care if you want to prevent unwanted puppies? To be on the safe side, you should keep a close eye on your female dog from the first signs of bleeding. In a healthy dog, this “critical phase” lasts around three weeks. The fertile days, during which pregnancy can occur, are significantly shorter. However, they cannot be clearly identified by laypeople.

Further topics

• About whelping and nursing puppies
• Mastitis in dogs (inflammation of the mammary glands)