How to know if your dog is on her period

Sara Farell
Sara Farell

There is no one definitive answer to this question, as there is no one way to determine if your dog is on her period. However, there are a few things you can do to help determine if your dog is on her period.

One way to determine if your dog is on her period is to take her to the veterinarian. The veterinarian can perform a blood test to determine if your dog is on her period. Additionally, the veterinarian may be able to tell you if your dog is experiencing any other symptoms, such as mood swings or changes in behavior, that may be indicative of her being on her period.

If you are unable to take your dog to the veterinarian, you can try to determine if she is on her period by observing her behavior. If you notice that your dog is behaving differently during her period, this may be an indication that she is on her period. Additionally, you may be able to tell if your dog is on her period by looking for changes in her urine. During her period, your dog's urine may be darker in color and may contain more blood.

When a female dog is "in heat," she is ready to breed and become pregnant. Estrus is the correct term for this stage of a female dog's reproductive cycle. While most dog owners who do not intend to breed their female dog choose to have her spayed, if you have recently adopted an intact female dog or intend to breed the dog, you should be aware of what to expect when your dog goes into heat.

A dog in heat may display symptoms such as bloody discharge, receptivity to male dogs, agitated behavior, and much more. An unspayed female dog in heat will exhibit different symptoms in each of the four stages. The most common sign that a dog is in heat is a bloody discharge, but it is not the only sign that your pup is ready to mate. Having an unspayed dog in your home can be difficult, especially if you also have an intact male dog, but knowing what to expect can help prevent problems from arising.

When Can I Expect My Dog to Have Her First Heat?

The age at which a dog's first heat cycle occurs varies greatly between breeds. Toy breeds can go into heat for the first time as young as four months, whereas large and giant breeds can be as old as two years before going into heat for the first time. Most dogs will have their first heat cycle between the ages of six and fifteen months.

What Are the Signs That My Dog Is In Heat?

The more you understand about your dog's cycle, the better prepared you will be for any physical or behavioral changes that may occur during her heat cycle. You will notice different changes during each phase of her heat cycle, which may include the seven signs listed below.:

  • Swollen vulva: The vulva is the opening to the dog's vagina. It is situated directly beneath the dog's anus. When your dog is in heat, the vulva swells and reddens. This can be very noticeable and frightening to dog owners who see it for the first time, but it is a normal part of estrus.
  • Bloody or straw-colored vulva discharge: When your dog is in heat, its vulva will discharge. The discharge is typically bloody at the start of estrus, and it may leave blood spots or stains on the dog's bedding, your furniture, or the floor. As estrus progresses, the discharge generally becomes more yellowish in color and decreases in quantity.
  • Receptive to male dogs: When your dog is in the midst of the estrus cycle, it will welcome male dog advances. Your dog will allow other dogs to mount her, may mount other dogs (including female dogs), and may even attempt to mount your leg or other pets in the house.
  • genital licking that is excessive: A female dog in heat will frequently lick her genital region much more than usual.
  • Agitated, nervous, or aggressive behavior: Your dog may appear skittish or nervous during the first phase of estrus. It may be aggressive toward other household pets or even you. As estrus progresses, your dog may become aggressive towards other female dogs while remaining friendly to male dogs.
  • Urinating more frequently: Dogs in heat urinate frequently to alert male dogs in the area that they are available for mating.
  • Change in tail position: Your female dog's tail may be tucked close to the body at the start of the heat cycle, but as estrus progresses, you'll notice your dog holding its tail to the side, alerting male dogs that she is ready for mating.

You can tell which stage of your female dog's heat cycle she is in by observing her physical appearance and behavior.

How to know if your dog is on her period
How to know if your dog is on her period

The Spruce / Lara Antal

What are the Canine Heat Cycle's Four Stages?

During your dog's heat cycle, she will go through four stages, each marked by changes in her body and behavior. The following are the four stages of the canine heat cycle::

  1. Proestrus: Proestrus is the beginning of the heat period, when your dog's body prepares to mate. A swollen vulva, blood-tinged discharge, excessive licking of the genital area, clingy behavior, and aggression toward male dogs are all symptoms of this stage. Your dog's tail may also be held close to her body.
  2. Estrus: The estrus phase is the mating period in which your female dog is receptive to males. You may notice your dog urinating more frequently than usual as she marks spots to indicate her readiness to breed. Although she may leave urine marks in places, her vaginal discharge will slow and may turn straw in color. Your dog will approach males with her tail held to the side when she is ready to mate, but she may be aggressive towards other females.
  3. Diestrus: This stage follows the "in heat" stage and allows your dog's body to either return to normal or develop into a pregnancy. Her vulva will revert to normal size, and the vaginal discharge will stop.
  4. Anestrus: Anestrus is a dormant phase with no signs of hormonal or sexual activity.

How Often Will My Dog Get Pregnant?

Dogs have two heat cycles per year, roughly six months apart. Some females' cycles will be irregular, especially if they are very young or very old. Small breeds can cycle three times a year, whereas giant breeds can only cycle once every twelve months. Canine estrous cycles, unlike those of some other species, are not affected by the seasons, sunlight, or temperature.

What Should I Do If My Dog Is Having a Heat Wave?

If your dog is going through her first heat cycle, it can be a stressful situation for both of you. Follow these guidelines to ensure that her heat runs as smoothly as possible.:

  • Never leave your dog alone in the yard. Do not underestimate a male dog's desire to locate a female releasing breeding pheromones. When you go outside, you might notice a strange male dog tied to your female.
  • When your dog is in heat, never let her off the leash. Although your dog may have excellent obedience skills, her recall ability may suffer when she is influenced by her hormones and is looking for a male.
  • Check that your dog's ID tags and microchip information are current. If your dog escapes from your yard or runs away, make sure you can be reunited with legible, updated ID tags and current microchip contact information.
  • If you notice any signs of illness, contact your veterinarian. A female dog's health may suffer after a heat cycle if the uterine lining thickens and produces more fluid, creating an ideal environment for bacterial growth. This can result in a potentially fatal pyometra, or uterine infection. A pyometra in a pet may cause excessive drinking or urination, thick vaginal discharge, a decreased appetite, abdominal pain, vomiting, or lethargy.
  • Consider spaying your dog once her heat cycle has passed. If you do not intend to breed your dog, consider spaying her after her heat cycle is over. Your veterinarian can advise you on the best age to spay your pet, and will most likely advise you to wait until she has completed her estrus phase before spaying her.

When Should I Have My Dog Spayed?

Although veterinarians used to recommend spaying your dog as young as four months old to ensure she never had a heat cycle and thus avoided mammary cancer, current research suggests that large- and giant-breed dogs should be allowed to grow before removing the hormones required for skeletal development. Before deciding on the appropriate age to spay your dog, consult with your veterinarian.

How Long Is a Dog's Heat Cycle?


  • How long can a dog be in heat?

    Dogs are in heat for approximately a week and a half to two weeks. Some dogs' estrus can last up to four weeks. However, your dog will not bleed or discharge for the duration of the heat cycle.

  • Can a dog become pregnant when she is not in heat?

    No, she cannot. Dogs can become pregnant only when they are in heat. While pregnancy is possible throughout the heat cycle, the dog is most fertile about a week after estrus starts. The window of maximum fertility lasts about five days.

  • When a dog is in heat, how do you keep the house clean?

    The best way to keep your house clean is to put your dog in a heat diaper, which will catch the blood she is excreting. It's also a good idea to keep your dog away from furniture and carpeted areas during this time, or to spread towels over areas your dog frequently visits.

If you suspect your pet is ill, contact your veterinarian right away. Always consult your veterinarian for health-related questions, as they have examined your pet, know the pet's medical history, and can make the best recommendations for your pet.

Article Sources

To back up the facts in our articles, The Spruce Pets only uses high-quality sources, including peer-reviewed studies. Learn more about how we fact-check and keep our content accurate, reliable, and trustworthy by reading our.

  1. Sato, Junko et al. Histopathology Of The Estrous Cycle Or Menstrual Cycle In Laboratory Animals. Journal of Toxicologic Pathology, Volume 29, Number 1. 3, 2016, pp. 155-162. Japanese Society of Toxicologic Pathology,

    What are the signs of a dog having her period?

    Dogs in heat exhibit the following characteristics.: .
    A large, red, swollen vulva.
    vulval bleeding (or a yellow/red/brown discharge).
    More licking of the back end than usual.
    Weeing more than usual.
    Behaviour changes such as: being excessively friendly to other dogs. roaming to find male dogs. mounting and humping.

    How long does dog menstruation last?

    Dog “periods” typically last about 2-4 weeks However, depending on your dog, the duration may vary. During this time, your dog may try to attract and mate with male dogs. If you're unsure what to do when your dog is in heat, consult with your veterinarian about having your dog spayed.

    Is it possible for a dog to have a period without bleeding?

    Silent Heat Cycle This occurs when your female has a heat cycle without the usual symptoms of bleeding and vulva swelling. Females will continue to be receptive to males and may become pregnant as a result. A silent heat cycle can be detected by your veterinarian using vaginal cytology and progesterone assays.

    What are the four stages of a dog's heat cycle?

    The canine estrous (reproductive) cycle is divided into four stages. These are proestrus, estrus, diestrus, and anestrus . Each stage has its own set of symptoms, including behavioral changes, physical or clinical changes, hormonal changes, physiologic changes, and cytologic (vaginal smear) changes.

dog period

Sara Farell Twitter

Social media ninja. Subtly charming troublemaker. Wannabe entrepreneur. Reader. Typical travel fanatic. Internet trailblazer. Extreme communicator.

Related Post

How to know if your dog is on her period

How know if your dog is pregnant

How to know if your dog is protecting you

How do you know if your dog have parvo

How to know if dog collar is to tight

How to know if a dog is too hot

Why does your dog rub her private on You?

How do you know if your dog has too much water?

How to know your dog likes you

How to know if my dog swallowed something