When I finish a puppy education course, the puppy has reached 6 months. In case the dog is a female, I explain how the dog season works. More and more scientific research confirms the importance of getting the female dog two or three cycles earlier if the owner decides to sterilize her. But every dog is different and I always suggest talking to the vet. Afterwards, I leave a number of details on the female’s cycle in relation to the characteristics of the owner’s dog that may be helpful in handling the situation without stress. The cycle creates changes in the dog’s body and mind.
Knowledge is a useful support in managing everything to do with the dog.’Knowledge is power’ said Francis Bacon, the 16th century English philosopher and scientist. Knowing how a dog’s mind and body works helps us to create a powerful relationship with him/her. It means a relationship based on trust, respect and love.
Today we provide information on the female dog’s season.
The female dog is a seasonal monoestral animal because she has only one estrous cycle per heat (on average two times a year). In contrast, the female cat is ‘seasonal polyestral’, i.e. it manifests heat on average every fortnight during the breeding season, from February to September.
The onset of heat in the dog is not influenced by the light/dark cycle as it is in the cat, for example. Artificial or tropical light (i.e. exposure to the sun for more than 12 hours) keeps hormone production stable and the cat can live in a constant heat state.
Do male dogs go into heat?
Heat in the male dog does not exist. Well, it is not understood as that of the female dog. The term “heat” in fact indicates the estrous phase of the bitch’s reproductive cycle, during which she is ready to breed and may become pregnant. When a male dog reaches sexual maturity, he is potentially always in heat. In fact, from 6 months ( or more for large dog) of age on wards, he is able to reproduce all year round.
Although one cannot speak of “male dogs in heat”, it is possible to notice major changes in their behavior if there is a female dog in the vicinity at the height of the oestrus period: these are induced by the pheromones she produces. Here are the most typical manifestations of a male sniffing a female in heat: he is restless and agitated, he often marks his territory by urinating frequently on surfaces and objects, he tries to run away, he has little appetite and is restless, he howls, cries or barks in an unusual way.
Can the dog’s heats be compared to the woman’s period cycle?
Not at all. In the woman, blood loss indicates the end of the ovum’s maturation cycle and thus indicates that ovulation has already taken place and is over, whereas in the dog it determines, on the contrary, the beginning of the fertile period and thus imminent ovulation.
When does the first heat begin?
The first heat in dogs begins when puberty sets in (puppy becomes a teenager). It means that it appears around the age of 6 months, but even then there is some variability linked to breed, size, selection (e.g. man-selected breeds like French Bulldog) and sometimes also environmental conditions. For example, stray dogs become sexually mature earlier than breed dogs.
The first heat can also be “anovulatory cycle”, which is typically referred to as false or split heat. In small bitches the first heat generally occurs earlier (between 6 and 12 months) than in large/giant sized bitches (between 9 and 14 months). Very small dogs can go into heat even around 4 months.
Are the cycles regular?
As long as the bitch is young, the heat cycles may be rather irregular and then stabilize within the first two years of life.
How often does the female dog go into heat?
Usually the female dog goes into heat twice a year, on average every 6 months. We must take into account that there is a subjective difference that influences the interval between two successive heatings (interestro), which may also be related to the breed (e.g. the Basenji female -primitive dog- manifests heat once a year) or the size of the dog. In fact, large dogs can go into heat once a year (e.g. Tibetan Mastiff). The important fact is that the heats must not appear at intervals of less than 4 months. If this happens it is important to talk to the vet.
Does it happen that a female dog does not go into heat?
It happens that a female does not go into heat, or skips it.
Why does this happen?
There can be many causes, from a hormonal dysfunction to much more serious gynecological problems, but also environmental, climatic causes and even nutritional deficiencies can undoubtedly play a role. When one is faced with a subject (male or female) that has fertility problems, it is necessary for the vet to investigate the problem thoroughly, by means of examinations, blood samples and subsequent laboratory analyses. Sometimes a simple antibiotic therapy or hormone treatment is enough and the problem is solved, but in other cases more invasive methods must be used.
Do female bitches bleed during their periods?
Yes. The first sign to look out for when the dog is in heat is vaginal bleeding. For some bitches the bleeding lasts 9/10 days and for others it lasts three weeks. When in heat, bitches show blood-coloured discharge and swelling of the vulva. The heat can last up to three weeks but the bleeding, which is initially dark red in color, becomes lighter as time passes until it disappears.
Can diapers be used?
Yes, when the dog is in the house to prevent it from dirtying. Usually small dogs do not leak much unlike medium/large dogs.
Diapers are not needed if the dogs clean themselves and if they do not bleed much (they only leak a few drops). Therefore, if the dog leaks a lot and does not clean itself well, it may be considered to use disposable diapers (without perfume because it may cause irritation) when then dog is at home. The disposable diapers should be changed once a day to avoid bacteria growth. There are also washable pants, but these too must be changed daily and washed at least at 60 degrees after each use.
It is best to leave her without diapers when she is on walks because the dog tends to urinate more and would be uncomfortable.
If you want to clean the bitch’s genitals from time to time, you can use a sponge with warm water. The sponge must be disinfected before and after use. You can put it in a container with boiling water (which has reached I00 degrees). Avoid wipes with chemical ingredients as they can irritate the vagina.
If you intend to use diapers, it is useful to socialize the bitch with these. Make her wear them 4/5 times for a few minutes every two or three days (for about 15 days). In this way she will easily accept them when she has her period.
Do diapers protect females from male dogs?
Dog diapers can help contain any discharge and keep your home clean during this time but not to avoid mating. The male dog finds ways to avoid diapers and does so quickly too.
Can the dog get wet when it is in heat?
Yes, the dog can walk/run in the sea or river. There is no risk.
Does the bitch have physical problems or experience pain during heat?
Although your dog will bleed, she does not feel pain during heat. Heat causes hormonal changes that affect both the female dog’s physiology and her behavior but does not induce complaints such as vomiting, diarrhea and incontinence. Should they occur over several days, a veterinary visit is recommended. On the other hand, it could be a bacterial infection if the bitch has white instead of red colored discharge and a bad smell. It is best to consult the vet immediately.
What is vaginal prolapse in female dog?
During heat, special attention must be paid to the swelling of the vulva, especially if it is a brachycephalic (e.g. French Bulldog) Vaginal prolapse is the protrusion of swollen vaginal tissue (as a donut shaped mass) through the vulva, the external female genital organ, during the heat cycle. So if you notice that the vulva is too swollen and the dog has difficulty peeing, take her to the vet.
Is there silent or asymptomatic heat?
If the female dog is not spayed and has normal reproductive health, she goes into heat with some regularity. However, it may happen that in the time interval in which oestrus is expected to return there is no sign of heat, as if the dog is delayed or skips her period at all. In these cases there can actually be silent, or asymptomatic heat, during which classic signs such as changes in behavior, swelling of the vulva and bleeding do not occur, or occur in such a mild form that they go unnoticed. It is possible to recognize this type of heat because male dogs also feel it and thus assume attitudes and behavior typical of courtship to the female. Asymptomatic heat is more frequent in young dogs and rather rare in older dogs. When, on the other hand, the dog skips heat, it is a good idea to consult the vet, as the causes could be certain disorders of the reproductive system.
Do bitches go through menopause?
As time passes, the interval between heats may increase, but female dogs do not go through menopause and continue to go into heat throughout their lives, unless they are neutered.
The bitch has managed to mate with a male dog. Is it possible to detach them during mating?
Absolutely not. You must let the dogs finish, without trying to detach them. If you try to detach them you risk creating very serious injuries to both dogs, due to the anatomy of the male mutating inside the female, not allowing detachment until they have finished copulating. In addition, dogs can be traumatized by the separation as it is very painful.
What to do if the female dog accidentally becomes pregnant?
The vet will make an ultrasound scan to check whether the bitch is pregnant. If it is decided not to keep her pregnant, an abortion can be performed. Use a pharmacological protocol that induces luteolysis or remove the luteotrophic support. There are short term physical side effects (such as wheezing, shaking, nausea and diarrhoea), but there is no negative impact on future reproductive potential. Alternatively, there can be ovariectomy (sterilisation) or ovariohysterectomy (which in addition to removing the ovaries also removes the uterus). Of course, the choice should be discussed with the vet to find what is best for the bitch. Every dog is different.
When the female has mated with a male, can she mate with other males?
Yes, there is superfecundation. This happens because the female’s ova remain available for fertilization during the same cycle even for several days. So, two or more eggs become fertilized by different mates. While pups from the same litter cannot be of different breeds, it is possible, however, for them to have different fathers. So some pups may be sired by one father and the rest by another male. To know the biological father, simply do a DNA test.
Are there any behaviors that indicate that the bitch is in heat?
Yes, the bitch changes her behavior.
She may show greater signs of affection towards you, excitement, jealousy towards other females, greater submissiveness, laziness, anxiety alternating with calmness or attempts to escape. Since the behavior in these cases varies greatly from dog to dog, we can take into account the behavior that manifests itself on a physical level:
1. Excessive licking
The fact that dogs lick themselves to wash themselves is completely normal behavior. But it is possible that the female dog is in heat if she starts licking her private parts excessively. This is due to swelling of the vulva and bleeding associated with the reproductive cycle.
2. Change in urination habits
The female dog urinates more often than usual, sometimes assumes a different position while urinating or raises her paw when she sees a male dog. She also tends to urinate when she encounters male dogs.
3. More sociable attitude towards male dogs
The bitch begins to attract males easily and is more friendly towards them. For example, during this period she may let males sniff and lick her vulva, which could not happen in a normal period. Excessive wagging of the tail is also a sign of availability towards male dogs: it is in fact a way that the bitch uses to indicate that she does not dislike physical contact. But she will not be available for mating until the estrous phase (about 7/9 days after the onset of heat).
4. Change in posture and tail position
When she enters the oestrus phase (approximately 7 to 9 days after the onset of heat) the bitch is available for mating and shows this by her posture and tail position. The bitch may assume positions designed to attract males and slightly raise her tail by moving it to the side. Some females provoke the male, engaging in a sort of game in which she approaches him and shows her bottom. The moment he approaches, she moves away.
5. Playing back mating movements
Male dogs tend to reproduce typical mating movements when they sense the sexual instinct. Similar behavior is also found among females when they are in heat. During this period, bitches may mount other dogs, regardless of their sex, or anything else they take for a dog.
6. Anxiety and agitation
The bitch may display anxious or even aggressive behavior and may become more jealous of her territory because she is preparing for a potential pregnancy.
How to deal with a bitch in heat?
Here are some tips
1. Do not humanize her
This is a normal physiological process. There is no need to protect the bitch too much. She can continue doing her activities. You just have to be careful not to stress her.
2. Use the long leash
Your dog can continue to explore the environment, but if male dogs approach, you can shorten the lead and walk away. The long lead will give her space to walk peacefully.
3. Make sure she has a good balance between activity and rest.
Some bitches are very tired and others are hyperactive. In the first case it is correct to let her rest more and add some extra mental games. In the second case, it is advisable to do calming activities and make sure she gets enough sleep.
4. Consult the vet if you are worried about something
5. Take walks in isolated, quiet places
6. Be patient if your dog shows signs of restlessness or nervousness.
How does heat work from a physiological perspective?
*video description at the end of the article
The estrous cycle corresponds to the physiological alternation of hormonal changes typical of the female that enable the organism to breed. In the female dog, the monoestral cycle consists of several phases. The duration of each phase depends on the breed and the dog’s characteristics:
–Proestrus is characterized by rapid follicular development and an increase in oestrogen and although its duration can vary from 3 to 17 days, for many dogs it does not exceed 9 days. It is the stage that most owners start noticing changes and when we say “the dog is in heat”. The first sign of this stage is swelling of the vulva. Bleeding begins, although it can vary from case to case, but is usually light in the first few days and then increases during the second part of the week During this phase the bitch is at the beginning of her reproductive cycle and it is easy to recognize the presence of an oedematous vulva with a slight bloody discharge.The bitch changes her behavior and may be more clingy with her owner at certain times and behave grumpily at others. Her eating habits also change. During this first period it frequently happens that the bitch eats little or seems much hungrier than usual.
The female begins to exert some attraction to the males. Pheromones (methyl-p-hydroxybenzoate) are present in the vaginal discharge that attract males but she is not ready to mount. As the bitch does not yet accept the male during this phase she tends to wrap her tail between her legs in order to protect her vulva. The female begins to exert some attraction to the males. Pheromones (methyl-p-hydroxybenzoate) are present in the vaginal discharge that attract males but she is not ready to mount.
Proestrus ends when the female gets mounted by the male. This happens in the next phase (Oestrus)
-Oestrus: this is the phase following proestrus. Ovulation occurs during this phase and lasts on average 9 days. Female dog accepts mating with male dog. This is the phase in which the bitch becomes fertile and the ovaries release the ova for fertilization. The secretions change from a deep red to a pinkish color. The vulva is less thick and becomes softer for penetration. Usually the female dog accepts the male by raising and moving her tail sideways when sniffed. The female dog starts flirting with the male (e.g. when a male dog meets the female), she turns around and shows him her bottom. At this point the male dog attempts to mount her.
This is when the female dog owner has to be most careful.
– Diestrus: in this phase the fertile part of the heat cycle is coming to an end. During this phase, which can last from 60 to 90 days, the bitch is no longer fertile. In the case of pregnancy, the diestrus phase lasts from the end of oestrus until the birth of the puppies (approx. 60 days). The swelling of the vulva disappears. The female dog is no longer interested in flirting.
– Anaestrus (or Interestrus): is the final phase of the bitch’s heat cycle. It is called the silent phase and occurs between one heat and the next. In the Anestrus phase the reproductive organs are at rest and prepare for a new cycle. It lasts between 3 and 5 months.
If you decide to sterilize your female dog, you must do so during this period, approximately 12 weeks after the start of the cycle. The decision to sterilize within 12 weeks is due to the fact that the female dog may experience a false pregnancy or hysterical pregnancy (an unspayed bitch undergoes the same hormonal changes as a pregnant bitch). It is also advisable to neuter the dog when it has reached sexual maturity, i.e. not before one year and eight months/two years (this also applies to male dogs) if there are no physical problems. However, this choice should always be discussed with your vet. We will talk about that in another article.
Hart, BL, Hart, LA, Thigpen, AP, Willits, NH (2020). Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence. Frontiers in Veterinary Science Volume 7
Bucci, R, Fusi, J, Robbe, D, Veronesi, MC, Carluccio, A (2022). Management of Vaginal Hyperplasia in Bitches by Bühner Suture. MDPI Journal 12, 24.
Concannon, PW (2011). Reproductive cycles of the domestic bitch. Animal Reproduction Science 124, 200–210.
Hollinshead, FK, Ontiveros, M, Burns, JC, Magee, C, Hanlon DW (2020). Factor influencing parentage ratio in canine dual-sired litters. Theriogenology 158, 24-30.
Lindh, L, Kowalewski, PM, Günzel-Apel, AR, Goericke-Pesch, S, Myllys, V, Schuler, G, Dahlbom, M, Lindeberg, H, Peltoniemi, OAT (2023). Ovarian and uterine changes during the oestrous cycle in female dogs. Reproduction, Fertility and Development 35(4) 321-337
Scully, CM (2023). Reproductive Management of the Female Small Animal. MSD Manual Veterinary Manual
The video is divided into three parts. There is a two-year-old whole male dog and a four-and-a-half-year-old female dog.
The male is mature physically but not psychologically.
The female has full psychophysical maturity.
The two dogs have known each other for a year.
In the first part the female begins to provoke the male. At this stage the female has not yet started her cycle. It started 3 days after this interaction.
The female gets sniffed but not approached. She provokes the male. The male does not understand the female’s intentions but gets excited and tries to discharge the tension by biting frozen mud.
In the second video, the female has started her period (swollen vulva and bleeding) but is not available for mating. Despite this, she provokes the male.
She provokes him, lets him sniff/lick her, and then moves away and so on. She is in the proestrus phase.
In the third video, the female is in the oestrus phase (it has been about 10 days since the onset of bleeding) and is ready for mating.
The male dog does not understand what he has to do and the female shows him, jumping on him.
In the following days, the male dog understands what to do and the dogs are separated because there was no intention to mate them.