Symptoms of a female dog in heat

Symptoms of dogs in heat vary throughout the cycle, and recognizing changes in her behavior and appearance is crucial if you are an owner of an un-spayed female dog.

Is your dog in heat? Not only is it helpful to recognize the beginning of the heat, but also to evaluate how the heat cycle is progressing.

Dog sniffing other dog's rear before they have sex, close-up
Photo by atiger

Separate stages of the heat cycle have different hormonal activity in your dog, which in turn results in various symptoms.

Early symptoms of dogs in heat

The first phase of the heat cycle in dogs is proestrus. Its name suggests that it’s something that happens before the “real” heat; however, it’s essential to recognize the signs during this stage, as they will be the first you notice.

Since the first day of the heat, you have to pay extra attention to your dog. Find 11 tips to handle a female dog in the heat here.

The first day of the heat is usually assumed to be the day you first notice the signs, while medically, more accurate would be the day when hormone estrogen starts to climb. Of course, you can’t see that wit ha naked eye, so signs are still the best option.

The first symptoms of a female dog in heat are as follows:

  • Red discharge from the vulva. This is often called spotting or bleeding. While it’s not what the medical world knows as “bleeding”, it indeed looks like one. During the first phase of the heat, the lining of the uterus is prepared to become receptive and becomes softer, which created red discharge. Sometimes it may be apparent, as you will see small spots on the floor, while often dogs clean themselves properly, and drops on the floor are less noticeable (at least in the beginning). An excellent way to check whether your dog is spotting is to wipe her vulva with a white napkin. Therefore, if it turns red, or pink, or, sometimes yellow, can tell that your dog’s heat cycle has begun. IMPORTANT: Discharges from the vulva can also be a sign of medical conditions, like inflammations, cysts, and even tumors. If this is the only sign you see, don’t assume your dog is in heat. If unsure, check with a vet.
  • Behavior changes. Since the beginning of the heat, your dog’s behavior may change. Most dogs become restless; however, it’s not a rarity when a dog becomes quite the opposite—less active. If your dog becomes restless, read our article on how to calm a female dog in heat. Also, since during the heat cycle, your female dog will be attractive to male dogs, she most likely will not be willing to breed. Therefore, it may cause aggression spurts towards other dogs, and sometimes towards people as well. Behavior changes, however, are not that apparent during the beginning of the heat and will get more pronounced during the second phase of the heat.
  • Enlargement of the vulva. Since the early days of the heat cycle, cells of the uterus of your dog will enlarge. This is visible from the outside as an enlargement of the vulva. The problem,  however, is, how would you know? Most dog owners don’t check that location often enough to know what it should look like. Shorthair dog owners will notice this symptom easier. If your dog is about to go in heat, you can also take a look at how it looks now, and then compare it to what you see later on. The way to check it for sure is vaginal cytology, which is done at a veterinary office. While a veterinary investigation is a more accurate way to tell whether your dog is in heat, it’s not always necessary.
  • Excessive licking. Your dog will lick her genital area more often than usual to clean all the discharge. If your dog is exceptionally tidy, you will not see spots on the floor, as described above. However, you should notice her licking herself too often if you pay at least some attention to your dog daily.
  • Appetite changes. Most dogs will have increased appetite during the heat, as the body requires additional energy; however, some dogs—especially those who become less active and lethargic—may show decreased appetite.
  • Temperature increase. Not always, but the body temperature of your dog may rise during the heat. However, remember that this may also indicate a wide range of medical conditions, but you indeed can measure your dog’s temperature at home, and in case of the heat cycle, the temperature may show to be higher than usual.

Symptoms of dogs in heat during the second phase

Now it becomes more exciting. Typically, about nine days after the heat begins (read more about the length of each stage of the heat here), your dog will enter the standing heat. This is something that is referred to as the “real heat” when the symptoms of your dog will intensify. However, it is not more real than other parts of the heat, but your dog will be attracted to males now.

Here are symptoms of the standing heat in dogs:

  • The dog will become willing to mate. While during the first phase, your dog may be reserved, and even act aggressively towards male dogs, she will now become both more attractive to males and more attracted to male dogs herself.
  • Symptoms of a dog in heat - acting crazy.
    Acting crazy is the most troubling sign of the heat cycle in dogs.

    Even more behavior changes. Was your dog restless during the first phase of the heat? Now she will go crazy. The explanation of this is simple. Your dog wants a specific thing, and she will not be calm until she gets it. She will express it through more activity, higher response to smaller noises, and excessive vocalization, including barking and howling, as well as gasping and sleep disorders. Hers. And yours, too. So it’s a great place to remind you about our article: “How to calm a female dog in heat“.

  • Tail wagging and changes in gait. Here’s a simple test to tell if your dog is in standing heat already. Scratch your dog’s lower back (just above the base of the tail) with your hand. If she pushes back and pushes her tail to the side, this is a symptom of standing the heat. Your dog may also swing her hips and wag her tail high up as she walks. This is an invitational move and is similar to very slutty flirting, in human terms, but it’s not that slutty in the dog world.
  • Discharge changes color. As the standing heat approaches, previously red discharge from the vulva may become pink, yellow, or even unnoticeable during the standing heat.
  • Vulva becomes softer, and swelling declines gradually. This may differ in some dogs, however.
  • Increased urination. This often appears during the first phase of the heat; however, it becomes more prominent during the standing heat. Urine is a marker and tells other dogs that the bitch is in heat. Therefore, your dog will dispense urine in smaller amounts over various locations. While this may also be a sign of a medical condition, you should not worry if other symptoms of the heat are present. Longhair dogs may also get their fur wet and stink of urine all the time.
  • Symptoms from the first phase of the heat, like appetite changes and increased body temperature, may remain during the second phase of the heat, too.

Are symptoms of dogs in heat reliable?

Usually, the presence of the above symptoms is enough information to know if your dog is in heat. However, you should note, the only sure way to tell if your dog is in heat is to run tests at a veterinary clinic.

  1. If the main reason you are looking up symptoms of female dogs in heat is to avoid unwanted pregnancy, the symptoms will give you enough information about times when you should be cautious (starting from the day you first notice signs).
  2. However, if you want to schedule the best day for breeding your dog, relying on symptoms will not be enough. In this case, you should run vaginal cytology and hormonal tests afterward.

Is your dog in heat? Identifying symptoms of dogs is heat is only one of the things you should be aware of. Take a look at our series about female dogs in heat for more tips and information.